Arsenal missed the chance to move back into the Premier League's top four and strengthen their hopes of Champions League football as they were stunned by Crystal Palace at Selhurst Park.
The Gunners would have moved above Tottenham with victory but fell behind early on through Jean-Philippe Mateta's header following a free-kick.
Things got worse for the visitors a few minutes later when Jordan Ayew got away from two Arsenal defenders and bent a shot beyond Aaron Ramsdale.
Arsenal were outfought and outworked in the first half, their only shot on target a Gabriel header at Palace goalkeeper Vicente Guaita.
The visitors showed improvement after the break and should have at least got one back as Martin Odegaard shot wide when unmarked inside the box, while Eddie Nketiah hit the woodwork.
Palace made sure of a hugely impressive win when Wilfried Zaha was brought down inside the box late on and the forward stepped up to convert the penalty.
The victory, Palace's first at home in the league in 2022, moves them up to ninth while Arsenal remain fifth and outside the top four on goal difference.
Source: BBC Sports