Southampton show some initiative early and win a corner to Joe Hart's right, but nothing comes of it for the visitors.
47'
IT'S BEEN A WHILE
West Ham's three-goal outburst in the first half marks the first time the Hammers have pulled off that feat in the top flight since September 2012 versus Fulham.
46'
SOUTHAMPTON SUB (1): LONG IN, GABBIADINI OUT
Southampton boss Mark Hughes has made his first switch of the match, bringing on Shane Long for Manolo Gabbiadini
46'
BACK TO ACTION IN EAST LONDON
Referee Jon Moss has blown his whistle to re-start the action here. Do Southampton have any fight left, or will West Ham continue to ooze class?
89'
Substitution
Josh Cullen (on). Cheikhou Kouyate (off). (West Ham United)
9'
WEST HAM SUB (1): FERNANDES IN FOR ANTONIO
Moyes has gone like for like to replace Antonio, introducing Edimilson Fernandes.
88'
WEST HAM SUB (3): CULLEN ON, KOUYATE OFF
And there is the official entry of Cullen into the match as he replaces an industrious Kouyate, who kept the Irons flowing through the midfield on the counter all match.
87'
CULLEN SET TO BE FINAL WEST HAM SUB
Moyes is giving instructions to Josh Cullen, who will be his final substitution to see out this match.
85'
WEST HAM TRYING TO PRESERVE CLEAN SHEET
Southampton enjoy a solid build-up in the final third, and Tadic sends in arguably his best cross of the day, but West Ham's defence is back in numbers, and they are able to work the ball clear of the penalty area and force the Saints to regroup without testing Hart.
83'
Substitution
Guido Carrillo (on). Charlie Austin (off). (Southampton)
83'
SOUTHAMPTON SUB (3): CARRILO ON, AUSTIN OFF
Hughes makes his final switch of the match as he introduces Guido Carrillo, with Austin making way.
82'
AUSTIN CUTS A FIGURE OF FRUSTRATION
The frustration is starting to show for Southampton, as Austin is fortunate not to be in Moss' book after scything down Masuaku with a thigh-high tackle near the sideline.
80'
Yellow Card
Dusan Tadic (Southampton)
80'
TADIC GOES INTO THE BOOK
Moss brandishes his yellow card to a third Southampton player, and this time it's to Tadic, who needlessly restricts Kouyate's progress in the middle of the pitch on the sideline.
80'
Substitution
Jordan Hugill (on). Marko Arnautovic (off). (West Ham United)
79'
WEST HAM SUB (2): HUGILL ON, ARNAUTOVIC OFF
And West Ham's two-goal striker gets a hero's reception as the Austria international makes way for Jordan Hugill for the final 10-plus minutes.
76'
ARNAUTOVIC TRIES AGAIN FOR A THIRD
Once Mario laid the ball off to him at the top of the box, everyone in the stadium knew Arnautovic was going to try for his third as he touched the ball to his right. That included Southampton, who had four defenders squeeze the space around him and resulted in a low, tame shot straight at McCarthy from 18 yards.
75'
BOUFAL RUN GOES FOR NAUGHT
Boufal's first meaningful touches result in an impressive run as he weaves around a pair of defenders before losing possession at the top of the box. He is then called for a foul as he tries to regain the ball, which in some ways is a perfect summation of Southampton's day at London Stadium.
72'
SOUTHAMPTON WIN CORNER
Tadic sends in an in-swinger from the right, but West Ham do well to mark and Hart has a clear lane to intercept the ball at the top of the six-yard box.
70'
SOUTHAMPTON LACKING INCISIVE PLAY IN FINAL THIRD
Southampton have seen a majority of the ball, their play in the final third has been seriously wanting with many overcooked crosses and just an overall lack of linking up in the penalty area to sternly test West Ham goalkeeper Joe Hart.
68'
SOUTHAMPTON SUB (2): BOUFAL IN, REDMOND OFF
Hughes makes his second swap of the match as Sofiane Boufal enters and Nathan Redmond departs.
Sitting on a hat trick, Arnautovic tries an ambitious curling right-footed shot from 20 yards that bounces wide of the right post from straight on. It was nice cross from Mario, who found acres of space on the left side.
7'
ANTONIO TO COME OFF WITH MUSCLE STRAIN
And it will be an early exit for West Ham attacking winger Michail Antonio, who may have strained his groin while attempting a long-range shot that was blocked before it got to goal. Hammers manager David Moyes is being pressed into an early substitution, as Antonio slowly walks off the pitch completely disappointed with the goings-on, covering his eyes with his shirt.
64'
WEST HAM ABSORBING, REACTING
West Ham are content to let Southampton have possession, and they have well to remain compact defensively in their own half. Still, Hammers may be wise to launch a counter or two just to stretch the Saints' backline.
62'
REDMOND HEADER ON CORNER GOES WIDE
Southampton finally get a shot for all their work in earning these corner kicks, but Redmond's header trying to get inside the left post has little power and loops over the end line and wide for a West Ham goal kick.
60'
ANOTHER CORNER FOR SOUTHAMPTON
Southampton win a corner to the left of Hart as Long has a shot deflected, but Tadic overcooks it, and West Ham's defence is able to defuse the danger before the visitors can put an effort on goal.
59'
Yellow Card
Jack Stephens (Southampton)
59'
BERTRAND GETS A YELLOW CARD
Southampton's Ryan Bertrand also goes afoul of Moss, being given a caution for a poor play on the ball while fouling Ogbonna.
6'
WEST HAM EARN CORNER
Stephens heads Cresswell's cross from the left over the line for a corner to McCarthy's right. The Irons have been on the front foot early with Antonio darting about and trying to make space for himself.
58'
SOUTHAMPTON WIN CORNER
The Saints again pour forward, and while they do earn a corner, Austin should have done more with a cross sent in from the right by Long, who did well to control a looping overhead pass before sending it smartly to the top of the box. Austin scuffed the first shot before having his second deflected for the corner. Again, though, nothing materialises.
55'
LEMINA GOES INTO THE BOOK
Moss brandishes his yellow card for the first time in this match, and Mario Lemina goes into the book after frustratingly punching the ball when Southampton are not awarded possession on the sideline.
54'
Yellow Card
Mario Lemina (Southampton)
46'
Substitution
Shane Long (on). Manolo Gabbiadini (off). (Southampton)
37'
WEST HAM GET FREE KICK DEEP ON THE LEFT
Masuaku earns the Hammers a free kick on the left below the 18-yard line as Redmond fouls him on a run. Mario has a go on goal, but his curling right-footed effort goes over the bar without giving McCarthy any worry.
36'
ARNAUTOVIC WINS WEST HAM CORNER
The Austria international has a cross from the left deflected over the end line for a corner. West Ham again go low and short, this time trying to play it to the top of the box, but a mix-up in signals has the ball going to an area missing West Ham players.
35'
HARD TO GAUGE HUGHES' IMPACT ON SOUTHAMPTON
There's only so much a new manager can do in two weeks, even with it coming at an international break, but Southampton have had so little of the ball in West Ham's half that it's difficult to tell what they have worked on in terms of attacking. They want to work down the left side against Zabaleta, but Redmond and Gabbiadini have been largely starved of service.
32'
ARNAUTOVIC AN EASY TARGET FORWARD TO FIND
Already a towering figure up front, Arnautovic is sporting what appears to be a platinum blonde, almost whitish hair colour that creates a stark contrast to West Ham's kit. It is quite difficult to lose the Austria international in the crowd.
30'
SOUTHGATE TAKING IN THE ACTION
After guiding England to a win over a Holland and a draw versus Italy as part of their Word Cup run-up, manager Gareth Southgate is in attendance at London Stadium. With Joe Hart getting the start between the sticks for the hosts, this may be a chance for the veteran goalkeeper to prove he deserves a spot on the plane to Russia.
28'
HAMMERS CORNER NEARLY CREATES THIRD
Hammers win a corner on the left, and after Mario's first effort is sent back to him, his second one creates enough confusion that McCarthy is fortunate enough to make a save with his legs. Arnautovic tries a side volley on that rebound but is flagged for offsides by the linesman.
27'
OTHER RESULTS HELPING WEST HAM
The out-of-town scoreboard is also going West Ham's way at the moment since Crystal Palace, level with Hammers on 30 points but now trailing them on goals scored, have already lost, and Swansea City, who have 31 points, are down two to Manchester United,
25'
SOUTHAMPTON MAKE RARE FORAY FORWARD
Southampton finally strung together a few passes and moved the ball down the left side of the pitch. Redmond had a cross deflected over the sideline for a throw-in, and the ball works its way to Gabbiadini, whose cross gets sent back out by the defence.
23'
HAMMERS CORNER
Fernandez earns the hosts a corner when his shot in the right side of the penalty area gets deflected over the line. Cresswel opts to play it short to Mario, but Southampton does well to react quickly and force a turnover as Cresswell loses possession over the end line for a Saints goal kick.
21'
ATMOSPHERE MORE CHEERY AT LONDON STADIUM WITH TWO GOALS
The crowd, which turned borderline feral towards owner David Sullivan, is in an understandably better mood after seeing their side strike for two goals. There is an added ring of security guards around the pitch to make sure there is not a repeat of the pitch invasions by irate supporters.
19'
ARNAUTOVIC BEING ATTENDED TO
About the only thing stopping West Ham at the moment are injuries, as recent goal-scorer Arnautovic is beeing looked at by the training staff for what could be a calf injury. He is walking on the sideline, and has been allowed back on the field by Moss.
17'
Goal
Marko Arnautovic (West Ham United)
17'
ARNAUTOVIC DOUBLES WEST HAM'S LEAD!!
And the Hammers are running riot at London Stadium! A horrible turnover by Southampton in their own pitch leads to Kouyate carrying the ball on the right. He leaves it for Mario, who has all sorts of time to send in a cross. Arnautovic drills a header that McCarthy does well to save at point-blank range, but the rebound falls right back to the striker and he makes no mistake finishing it from close. WEST HAM UNITED 2, SOUTHAMPTON 0
3'
MCCARTHY CALLED INTO EARLY ACTION
The Southampton keeper turns away a sharp-angled shot from inside the box after a cross by Antonio was turned left with a wayward low volley by Zabaleta.
16'
ARNAUTOVIC NEARLY DOUBLES WEST HAM'S ADVANTAGE
And Southampton are fortunate they are not down two as Arnautovic narrowly goes wide after being sent through by Noble. Arnautovic tried to go inside the right post but put it just wide.
13'
Goal
Joao Mario. Assist by Cheikhou Kouyate (West Ham United)
13'
JOAO MARIO PUTS WEST HAM ON THE BOARD
And the hosts have struck first through Joao Mario. He started the play by helping pry the ball from Mario Lemina in West Ham's half of the pitch. It got out to Kouyate, who thundered down the right side of the pitch before cutting it back to the top of the box. Mario had all sorts of time to settle it before unleashing a rasping right-footed drive from just inside the box that McCarthy got a glove on but could not stop before it crashed into the net. WEST HAM UNITED 1, SOUTHAMPTON 0
45'
Goal
Marko Arnautovic. Assist by Arthur Masuaku (West Ham United)
45'
HALFTIME: WEST HAM UNITED 3, SOUTHAMPTON 0
Referee Jon Moss has blown his whistle to end the first half, and it would seem, mercifully for Southampton. The visitors have shown little fight under new boss Mark Hughes and even less care of the ball as Hammers have run rampant in all areas of the pitch. It's a deserved 3-0 lead thanks to some classical finishing by Arnautovic after a well-taken first goal by Mario. The lone negative was Antonio having to be removed less than 10 minutes into the contest through injury.
45'
AND ARNAUTOVIC MAKES IT 3-0!
And West Ham have all but secured the three points before Jon Moss blows his halftime whistle as Arnautovic strikes again! Masuaku sends in a lovely cross from the left as West Ham moved like quicksilver on the counter, and Arnautovic puts his right foot out and properly sends it past a helpless McCarthy and inside the right post from 10 yards to complete a brace. WEST HAM UNITED 3, SOUTHAMPTON 0.
45'
FIVE MINUTES OF STOPPAGE TIME
The fourth official has signaled for five minutes of stoppage time, in large part due to Antonio's early exit because of injury.
90'
FINAL: WEST HAM UNITED 3, SOUTHAMPTON 0
What a difference three weeks has made at London Stadium. After the chaos of a pitch invasion and unruly fans, a brace by Marco Arnautovic has everyone blowing bubbles again for West Ham, who climb to 14th on 33 points with a comprehensive 3-0 victory. It was full marks to the hosts, who were brilliant on the counter and overcame the early loss of playmaker Michail Antonio to injury. For Southampton, who remain at the top of the drop on 28 points, there is plenty of work to do after a listless first 45 minutes in Mark Hughes' debut as there was a complete lack of sharpness in the final third throughout. Thanks for following along and see you all again real soon!
90'
LONG HEADER GOES WIDE
Cedric sends in a cross from the right, and while Long is able to squeeze between two defenders to get his head to it, it lacks power and goes wide of the right post.
90'
WEST HAM EARN FREE KICK ON THE RIGHT
Hammers midfielder Mark Noble has earned a free kick deep on the right about six yards above the end line. Mario sends it across above the top of the box, and Cresswell sends a crackling left-footed volley that slices away from McCarthy and thumps the crossbar before going out of play. Very nice set piece there from the pair.
90'
THREE MINUTES OF STOPPAGE TIME
The fourth official has signaled three minutes of stoppage time.
40'
REDMOND AND KOUYATE GIVEN A TALKING TO BY MOSS
After Kouyate lost the ball on the sidelines, Redmond gave the Hammers midfielder a shove as he re-started play. Kouyate takes exception and shoves back, and the two have a little back-and-forth before Moss intervenes. No handbags or anything of that nature, but Redmond definitely is a little tetchy with his side down two.
4'
HUGHES MAKES DEBUT WITH CHALLENGING TASK
It may be Mission: Impossible for Mark Hughes, who has been tasked with trying to rescue Southampton from the drop over the final eight matches. The Saints are at the top of the drop on 28 points, one better than Stoke City, but a victory here could lift them as high as 14th pending other results on this matchday.
9'
Substitution
Edimilson Fernandes (on). Michail Antonio (off). (West Ham United)
43'
CRESSWELL TRIES TO CATCH MCCARTHY OUT
West Ham do well to stretch the field with a long cross-pitch pass to Masuaku, who lays it off to Cresswell. He tries a looping shot aiming for inside the right post from about 25 yards trying to catch McCarthy off his line, but it goes over the bar for a Southampton goal kick.
53'
SOUTHAMPTON WINNING MORE 50-50 BALLS
While it's uncertain if Hughes peeled any paint with his halftime speech, Southampton definitely have been showing a little more zeal in their efforts.
50'
SOUTHAMPTON WIN A SECOND CORNER
Southampton continue to press forward with urgency as Austin wins a corner after his shot was deflected by a sliding defence after a smart pass from Tadic sent him inside the penalty area. Tadic sends it in from the right, and Hart calmly gets a fist to it for another corner. This out-swinger, though, is cleared by West Ham's defence.
50'
LONG TRYING TO MAKE IMPACT
Saints sub Long is trying to make an impact and nearly sent Austin through before the defence caught up.
12'
SOUTHAMPTON GAIN CORNER
The visitors are gifted a corner when Kouyate needlessly plays it over the end line. Southampton play it short and nothing happens.
11'
JON MOSS YOUR MAN IN THE MIDDLE
Jon Moss is overseeing the action at London Stadium and has just awarded a free kick to Southampton after a foul on Zabaleta. The outswinger towards the far post is knocked from danger.
10'
WEST HAM EARN SECOND CORNER, BUT NOTHING MATERIALISES
West Ham earned a second corner after McCarthy got a glove on Cresswell's first effort, but this time, the defence does its job on a low in-swinger and clears their lines.
1'
PLENTY AT STAKE AT LONDON STADIUM
This is the quintessential six-point relegation belter, with West Ham entering this match just above the drop on 30 points, trailing Crystal Palace on goal difference while also being one spot above the Saints.
1'
UNDERWAY AT WEST HAM!
The referee has blown his whistle and we are underway as West Ham United host Southampton.