West Ham were relegated from the English Premier League after squandering a 2-0 lead in a 3-2 defeat away to fellow strugglers Wigan on Sunday.
Senegal striker Demba Ba's first half double gave West Ham hope in a match they had to win to set up a chance of a last day reprieve against Sunderland next weekend.
But Wigan, who stayed second bottom, hit back through Charles N'Zogbia's blistering 57th minute free-kick before substitute Conor Sammon drew the hosts level at the DW Stadium 11 minutes later.
N'Zogbia then sealed Wigan's remarkable recovery in stoppage time when he slid a shot under the body of England goalkeeper Robert Green, who had previously made several fine saves.
Defeat left the Hammers on 33 points, meaning a win against Sunderland would not be enough for the London club to climb out of the relegation zone.
Wigan though could yet avoid the drop if they get a draw or better against Stoke and other results go their way.
In all, five clubs were left within a point of each other as they faced a frantic finale to stay in the top flight.
Wigan and Blackpool were in the relegation zone on 39 points. Birmingham, beaten 2-0 by Fulham on Sunday, also had 39 points but were above the bottom three on goal difference alone.
Meanwhile Blackburn and Wolves, on 40 points apiece, were still not assured of avoiding relegation ahead of their meeting at Molineux.
Birmingham's survival prospects were dealt a blow when Brede Hangeland headed in from a fifth minute corner before the central defender doubled Fulham's lead in the 49th minute.
At the top of the table, Arsenal's hopes of a second-place finish ended with a match to spare following a 2-1 home loss to Aston Villa as England striker Darren Bent scored twice early in the first half before Robin Van Persie pulled a goal back in the 89th minute.
Defeat left the Gunners four points adrift of second-placed Chelsea, who earlier Sunday gave their London rivals hope by conceding a late equaliser in a 2-2 draw with Newcastle.
Arsenal could now miss out on the top three finish needed to guarantee a Champions League group stage spot and avoid the qualifying round, with fourth-placed Manchester City just two points behind with a game in hand.
FA Cup winners City play Stoke at Eastlands on Tuesday in a repeat of Saturday's Wembley final.
Elsewhere, Tottenham Hotspur moved into pole position for a place in the Europa League after a 2-0 win away to Liverpool, playing their first match since Kenny Dalglish was named as their permanent manger, moved them a point in front of their rivals for a spot in the second-tier tournament.
Dutch midfielder Rafael van der Vaart fired Tottenham into a ninth minute lead with a fierce shot into the top corner from the edge of the box.
World Cup final referee Howard Webb then angered the Anfield faithful by awarding a penalty after what seemed like a shoulder charge between Liverpool's John Flanagan and Spurs' Steven Pienaar.
Luka Modric then struck the 56th minute spot-kick down the middle to double Tottenham's lead.
Chelsea had seen their slim hopes of retaining the title ended by champions United's 1-1 draw away to Blackburn Rovers on Saturday.
But they responded by going ahead as early as the second minute through defender Branislav Ivanovic at Stamford Bridge.
However, Newcastle equalised eight minutes later through Argentina midfielder Jonas Gutierrez.
Chelsea though regained the lead seven minutes from time when a mistake by Newcastle goalkeeper Tim Krul, who misjudged a Frank Lampard free-kick, allowed Brazilian defender Alex to head in at the far post.
But Newcastle defender Steven Taylor headed in from close range shortly before the final whistle.