Arsenal lost a Premier League match against Southampton, squandering a golden opportunity to draw level with Tottenham Hotspur in the race for fourth place.
Arsenal had the chance to reach 57 points and have a game in hand over their rivals after Spurs lost at home to Brighton earlier in the day.
Despite a good start and a powerful finish, Mikel Arteta’s players lacked intensity when faced with the task at hand.
Jan Bednarek scored the game-winning goal against the run of play just before halftime, lashing home from close range after good work from Mohamed Elyounoussi.
Arsenal had already squandered two wonderful chances to break the stalemate, with Saints goalkeeper Fraser Forster making two outstanding stops to deny the visitors.
Forster dived low to his right to stop Gabriel Martinelli and then high to his right to stop Bukayo Saka from close range, who really should have done better.
In the second half, Forster was just as difficult to beat, with Eddie Nketiah, Saka, and Granit Xhaka all coming close.
Arteta’s side have now lost three games in a row, giving Manchester United an advantage in the hunt for a Champions League spot.