Manchester City can be crowned champions with one more win or if Arsenal lose at Nottingham Forest on Saturday.
Arsenal’s fading Premier League titles hopes are all but over after second-half goals by Julio Enciso, Deniz Undav and Pervis Estupinan earned Brighton a stunning 3-0 win at the Emirates.
The result means Manchester City only need one more victory from their final three games to defend their crown and they could be confirmed as champions as early as Saturday night if Mikel Arteta’s side lose at Nottingham Forest.
Arteta admitted pre-match it was must-win for Arsenal but they tasted defeat after a promising first-half showing thanks to Enciso’s 51st-minute header and late efforts by Undav and Estupinan.
It keeps alive the faint top-four hopes of Roberto De Zerbi’s team, who claimed another scalp in their outstanding season to move up to sixth with games in hand on Liverpool, Manchester United and Newcastle.
Any hope Arsenal had of Manchester City dropping points at Goodison Park was dispelled even before Arteta had named his starting line-up with their title rivals 3-0 up after 51 minutes.
It failed to dampen the atmosphere at the Emirates but visiting Brighton were not in London to make up the numbers and had European football ambitions to get back on track following a shock home loss to Everton on Monday.
The opening exchanges were affected by stoppages but referee Andrew Madley seemed keen to keep his cards in his pockets with Gabriel Martinelli and Moises Caicedo lucky to avoid punishment for poor challenges.
Caicedo, who saw a move to Arsenal fall through in January, in a less-familiar right-back role caught Martinelli after seven minutes and it eventually forced the Brazilian off with only 19 minutes played.
Enciso had tested Aaron Ramsdale with a firm near-post effort by this point and Martin Odegaard had sent a low strike wide but the contest had failed to get going following a stop-start opening.
Arsenal slowly got into their groove and Jason Steele had to kick away a Gabriel Jesus shot from a narrow angle before substitute Leandro Trossard went close against his old club.
Trossard, a replacement for Martinelli, was booed by the away fans and nearly gained payback after half an hour when Odegaard and Granit Xhaka exchanged passes to find the Belgian, but his swerving effort clipped the top of the crossbar from 16 yards.
Brighton improved after that let-off and Enciso should have done better when Kaoru Mitoma skinned Ben White and teed up the Paraguayan, but he scooped over on the turn.
Teenage forward Evan Ferguson also fired wide soon after for the Seagulls before Bukayo Saka dragged a shot off target from a promising position inside the area in first-half stoppage-time to ensure it remained goalless at the break.
It only took six minutes of the second half for Arsenal’s profligacy to be punished.
Mitoma found the overlapping Estupinan, who had not been tracked by Saka, on the left but after his first delivery had been half-cleared, his scuffed follow-up cross found its way to Enciso, who headed home.
Enciso was only unmarked because Arsenal centre-back Jakub Kiwior was in a heap on the floor after he twisted his ankle after Estupinan’s first centre but Brighton nor Manchester City cared one bit.
Kiwior was fine to carry on but Arteta had seen enough and introduced Thomas Partey and Reiss Nelson on the hour mark.
Substitute Nelson immediately made an impression with a low shot flashed wide and yet emotions were starting to spill over at the Emirates.
Arteta received a booking and while Trossard fired straight at Steele minutes later, Brighton remained in control and the Arsenal boss made his final roll of the dice with 13 minutes left.
Jesus and Odegaard made way for Eddie Nketiah and Emile Smith Rowe while De Zerbi introduced Facundo Buonanotte for Brighton.
And with four minutes left it was good night to Arsenal’s title challenge when Trossard’s intended flicked pass hit Pascal Gross and ricocheted into the path of Undav, who lobbed over Ramsdale.
De Zerbi sprinted down the touchline to celebrate and was at it again deep into stoppage-time when Estupinan capped a fine display with a first Brighton goal after he fired home on the rebound when Ramsdale spilled Undav’s effort.