The tempo slowed after the opener as Arsenal kept control without moving out of third gear and United unable to kick on, with direct, skilful Diallo their biggest threat
Arsenal returned to the top of the Premier League as Leandro Trossard’s goal proved enough to inflict further misery on Manchester United.
Manchester City temporarily usurped the Gunners with their win at Fulham on Saturday lunchtime, meaning Mikel Arteta’s men could ill afford any kind of slip up at Old Trafford.
United made Arsenal sweat more than most predicted on Sunday, when Trossard’s tap-in after Casemiro’s latest defensive error secured a 1-0 win in their penultimate match of their season.
City will go back top of the pile if they win their game in hand at Tottenham on Tuesday but this result ensures the Premier League title race will go down to the final day.
Arsenal were far from their best at Old Trafford, where makeshift centre-back Casemiro’s slowness to push out and then react to having played Kai Havertz onside led to Trossard’s first-half winner.
It was their 14th loss of a poor Premier League campaign and a ninth home defeat in all competitions – the joint most in the club’s history – further denting their hopes of European qualification with two to play before the FA Cup final against Manchester City on May 25.
The women’s edition was held at Wembley on Sunday but Sir Jim Ratcliffe plumped for the Arsenal match as fellow co-owner Avram Glazer attended the 4-0 win against Spurs for Marc Skinner’s side.
Arsenal – unchanged for a fourth straight game – had an early shot through Bukayo Saka but it was far from one-way traffic as United’s hodgepodge team threatened a shock.
Rasmus Hojlund slipped and blasted over after Thomas Partey was dispossessed, before quick feet from Amad Diallo – making his first Premier League start since May 2021 – led to Alejandro Garnacho striking over.
There were a few unsteady early moments from Arsenal goalkeeper David Raya and Trossard sent the ball whistling narrowly wide of his own goal as he cut out a Diogo Dalot ball.
Onana’s long ball forwards was nodded wide by William Saliba to Ben White, who played a clipped ball down the right flank to Havertz.
The Germany international was played onside by the cumbersome Casemiro, who was too slow to push up and then poorly positioned as Trossard steered home a cutback from close range.
The tempo slowed after the opener as Arsenal kept control without moving out of third gear and United unable to kick on, with direct, skilful Diallo their biggest threat.
The winger had a penalty appeal rejected as half-time approached following a challenge from Partey.
Aaron Wan-Bissaka blocked a Declan Rice stinger and Saliba headed over when play resumed, with United fans chanting defiantly as they tried to inspire their side to an equaliser.
Garnacho wasted a good chance when bending wide from the edge of the box, then at the other end quick Arsenal play ended with Onana getting down to deny captain Martin Odegaard.
Substitute Antony saw a bobbling shot saved and Garnacho struck the side-netting before Onana brilliantly denied Gabriel Martinelli as play continued to swing from end-to-end.
United’s goalkeeper was impressing between the sticks, preventing Aaron Wan-Bissaka from scoring an own goal and then reacting to save from Rice.
Thunder echoed around the ground and the heavens opened as the clock wound down at Old Trafford, where the nervy visiting fans avoided being caught by a late bolt from the blue.