Manchester United moved to within nine points of runaway league leaders Manchester City with a 1-0 win at Burnley on Saturday. A game where United midfielder Henrikh Mkhitaryan, the proposed makeweight in the Sanchez deal, was left out by Jose Mourinho, was goalless until the 54th minute when Anthony Martial scored with a shot that went in off the crossbar.
With Sanchez moving slowly but surely towards a 48.5 million dollars transfer to Premier League rivals Manchester United, Gunners manager Arsene Wenger left him out of his matchday squad.
Any fears Arsenal would struggle up front without Sanchez proved groundless as they surged into a 4-0 lead inside 22 minutes at the Emirates Stadium.
It took Arsenal just six minutes to open the scoring, an unmarked Nacho Monreal heading in from a corner. Things didn't get any better for a Palace side managed by former England boss Roy Hodgson.
Monreal turned provider for Alex Iwobi before Laurent Koscielny scored Arsenal's third goal.
Palace's defence gave way again when a sweeping move involving Mesut Ozil and Jack Wilshere ended with the onrushing Alexandre Lacazette firing home from 12 yards.
But Luka Milivojevic's volley 12 minutes from time denied Arsenal goalkeeper Petr Cech a clean sheet.
On a day when all Premier League fixtures were preceded by a minute's applause in memory of the former West Bromwich Albion and England forward Cyrille Regis, a trailblazer for black players who died aged 59 last week, the Baggies drew 1-1 with Everton.
Jay Rodriguez's put West Brom 1-0 up in the seventh minute but Theo Walcott, on his Everton debut following his midweek move from Arsenal, headed into the path of fellow substitute Oumar Niasse, who volleyed in a 70th-minute equaliser.
But the sight of Toffees midfielder James McCarthy going off with a broken leg cast a shadow over Everton boss Sam Allardyce's 1,000th game as a manager.
Stoke gave new manager Paul Lambert victory in his first game in charge as they climbed out of the relegation zone with a 2-0 win at home to Huddersfield.
Joe Allen opened the scoring in the 53rd minute before Lambert, who replaced the sacked Mark Hughes, saw the Potters double their lead through Mame Biram Diouf.
Leicester also beat Watford 2-0, Jamie Vardy scoring from the penalty spot six minutes before the break after the England striker was brought down in the box.
The score stayed at 1-0 until Riyad Mahrez put the result beyond doubt in second-half stoppage time.
West Ham and Bournemouth shared the spoils in a 1-1 draw at the London Stadium as both clubs inched their way further clear of the bottom three.
Ryan Fraser put Bournemouth ahead in the 71st minute but the lead evaporated after just over a minute, with substitute Javier Hernandez drawing the Hammers level.
Tottenham Hotspur continue their quest for a Champions League place on Sunday when manager Mauricio Pochettino returns to former club Southampton.
(With AFP Inputs)