Everton's top-four hopes suffered a blow as they crashed to a surprise 3-2 defeat at Goodison Park against Crystal Palace, whose Barclays Premier League 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.
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.
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.
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.