Yannick Bolasie's late equaliser saw Crystal Palace take a point from Arsenal to prevent the Gunners from moving back into third place in the Barclays Premier League.
A largely forgettable afternoon ended with drama as Bolasie arrowed in a shot which should have been dealt with by the recalled Petr Cech, cancelling out Alexis Sanchez's opener on the stroke of half-time.
The 1-1 draw sees Arsene Wenger's men draw level on points with Manchester City, but they remain fourth due to an inferior goal difference.
Wenger had been criticised for sticking with David Ospina in goal despite Cech's return from injury, but it was the former Chelsea man who was culpable for an equaliser from Alan Pardew's FA Cup semi-finalists.
The visitors had largely played on the back foot but will welcome a share of the spoils after both Sunderland and Newcastle won on Saturday.
Cech made the game's first save with almost half an hour gone as he easily held onto Bolasie's tame effort before Sanchez saw a 25-yard free-kick clip off the wall and fly just wide of Wayne Hennessey's right-hand post.
The Wales goalkeeper was finally forced into action just minutes before the break as Sanchez poked a pass through to Mesut Ozil, whose shot was kept out by the legs of Hennessey.
Connor Wickham then spurned Palace's best chance of the opening 45 minutes, miscuing a free header inside the Arsenal box just before Sanchez showed him how it was done at the other end.
Danny Welbeck robbed the ball from Palace skipper Mile Jedinak before dinking in a cross which Sanchez looped over Hennessey with his head for his third goal in three games.
Pardew introduced Bakary Sako for Jedinak at half-time but the game continued to follow the same pattern, Alex Iwobi heading wide from Francis Coquelin's cross with Arsenal again dominant.
Ozil came within a whisker of adding the second with a well-taken free-kick but it remained an afternoon of toiling with the Gunners' attacking talent.
Former Arsenal man Emmanuel Adebayor was introduced to a chorus of jeers just before Hennessey did well to stop Welbeck scoring from close range.
Sanchez almost added a second after reacting quickly to the award of a free-kick and racing in to meet Ozil's set-piece, diverting a header wide.
With the Eagles pushing more men forward in the hope of grabbing an equaliser, Sako saw a header tipped over the crossbar superbly by Cech.
Arsenal's own substitute Olivier Giroud should have done better when presented with the ball, with Sanchez then sending a shot well wide.
And it was not long until Palace made their hosts pay for their profligacy as Adedayor fed Bolasie, who fired in a shot that Cech should have saved but which squirmed past the Czech Republic international and into the corner of the net.
It could have been all three points for Pardew's side as Wilfried Zaha burst into the box in stoppage time only to be stopped by a last-gasp Gabriel challenge.
The leveller leaves Arsenal on 499 Premier League wins and just four points clear of the chasing pack as their hopes of a 20th consecutive top-four finish remains in the balance.
TWEET OF THE MATCH
TV presenter and Crystal Palace fan Susanna Reid: " That sort of felt like a win #cpfc"
PLAYER RATINGS
Arsenal
Petr Cech: 5/10
Hector Bellerin: 6
Gabriel: 6
Laurent Koscielny: 6
Nacho Monreal: 6
Mohamed Elneny: 6
Francis Coquelin: 6
Mesut Ozil: 6
Alex Iwobi: 7
Alexis Sanchez: 7
Danny Welbeck: 7
Substitutes
Aaron Ramsey (for Iwobi, 75): 5
Olivier Giroud (for Welbeck, 75): 5
Theo Walcott (for Elneny, ): 5
Crystal Palace
Wayne Hennessey: 6
Joel Ward: 6
Scott Dann: 5
Damien Delaney: 6
Pape Souare: 5
Joe Ledley: 5
Mile Jedinak: 5
Jason Puncheon: 5
Yohan Cabaye: 5
Yannick Bolasie: 6
Connor Wickham: 5
Substitutes
Bakary Sako (for Jedinak, 46): 5
Emmanuel Adebayor (for Wickham, 64): 6
Wilfried Zaha (for Puncheon, 75): 6
STAR PLAYER
Alexis Sanchez. Buzzed around energetically and pestered the Palace rearguard, but rarely were his team-mates on his wavelength.
MOMENT OF THE MATCH
Welbeck harassed a dithering Dann into a hospital pass to Jedinak and then robbed the Australian. The England forward then floated the ball over for Sanchez to send a looping header over Hennessey.
VIEW FROM THE BENCH
Arsenal's sole change following the draw at West Ham was the return of Cech in goal, while Palace made two changes, with Wickham and Ledley in for the injured Dwight Gayle and Zaha, who was on the bench despite a knock. The Eagles continually coughed up possession and Jedinak was sacrificed at half-time for Sako. Ledley moved into the middle and Sako's pace was used as an outlet. Zaha's introduction improved Palace and Adebayor was poor apart from in setting up the equaliser. Giroud, Ramsey and Walcott all had points to prove, but none of them did so.
MOAN OF THE MATCH
It has been almost seven years since Adebayor left Arsenal. He was jeered as if it were yesterday, but Gunners fans would have been better using their energy to urge on their team. The Togolese appeared to try to curry favour with his former employers by relinquishing possession swiftly. The one time he held on to the ball he provided the pass from which Bolasie scored.
WHO'S UP NEXT
Arsenal v West Brom (Barclays Premier League, Thursday, April 21)
Manchester United v Crystal Palace (Barclays Premier League, Wednesday, April 20)
Source: PA
