Manchester City saw their title hopes take a huge blow after being held to a home 2-2 draw by bottom club Sunderland.
If Sunday's defeat at the hands of Liverpool had deeply wounded City's chances then this frenetic 2-2 draw could prove the killer blow.
As for Gus Poyet's Sunderland, who came into this match on the back of a run that had seen the Black Cats lose five on the bounce, their survival hopes remain alive, if only just.
Manuel Pellegrini's men, sorely missing the injured David Silva and Yaya Toure, are now six points behind leaders Liverpool with a game in hand.
Barclays Prem
1 Liverpool 77
2 Chelsea 75
3 Man City 71
4 Arsenal 67
5 Everton 66
6 Tottenham 60
7 Man Utd 57
8 Southampton 48
9 Newcastle 46
10 Stoke City 43
11 C Palace 40
12 West Ham 37
13 Hull City 36
14 A Villa 34
15 Swansea 33
16 West Brom 33
17 Norwich 32
18 Fulham 30
19 Cardiff 29
20 Sunderland 26
City had taken an early lead through Fernandinho, and had appeared to have held off Sunderland's challenge until two fine goals by Connor Wickham in the second half threatened a real upset.
Samir Nasri grabbed a point with a late equaliser but then missed a glorious chance for a winner as City's hopes of making up lost ground faded.
Everton's top-four hopes suffered a blow as they crashed to a surprise 3-2 defeat at Goodison Park against Crystal Palace, whose survival now appears assured.
The Toffees had been looking to take the opportunity to leapfrog Arsenal into fourth place in the race for Champions League football.
But instead they remain fifth - a point behind the Gunners, with both clubs having four more games to go - after they were undone by a Palace side who were worthy victors of an absorbing contest.
Tony Pulis' men deservedly went in at half-time with a 1-0 lead thanks to Jason Puncheon's strike from Marouane Chamakh's assist in the 23rd minute - his fourth goal in the past three matches - after Tim Howard had parried a cross from Yannick Bolasie.
The dangerous Bolasie then provided the corner from which Scott Dann sent a free header past Howard four minutes after the interval to make it 2-0.
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Substitute Steven Naismith reduced the deficit with a close-range finish in the 61st minute, but Cameron Jerome restored Palace's two-goal cushion in the 73rd.
Kevin Mirallas' effort with four minutes of normal time remaining then set up a nervy finale which Palace managed to come through with their lead intact and another vital three points secured.
The result, Everton's first home loss since Boxing Day and only their second all season, brought their seven-match top-flight winning streak to an end.
Palace's own run of victories, meanwhile, extended to four games as they moved up to 11th, on to 40 points - the total widely regarded as a guarantee of safety - and 10 points clear of the relegation zone, with four more fixtures left.