Emi Buendia netted with the final kick of the match as Aston Villa shocked Arsenal, closing in to just three points from the Premier League leaders.
Leandro Trossard’s sixth goal of the season seemed to have secured a point for Arsenal after he equalized Matty Cash’s opener.
However, Buendia scored in the 95th minute, helping Unai Emery’s team rise to second place in the standings.
Arsenal, who dominated Bayern Munich and Tottenham last month, experienced their first league loss since falling 1-0 to Liverpool in August.
Villa Park exploded when substitute Buendia netted, marking Villa’s seventh consecutive match across all competitions.
Eberechi Eze’s goal was ruled out for offside before the home team gained a first-half advantage as Arsenal, particularly Eze, lost focus, allowing Cash to score at the far post.
Arsenal came back revitalized post-break as Mikel Arteta brought on Viktor Gyokeres and Trossard, who equalized with his 50th Premier League goal after previously coming close.
Emi Martinez expertly pushed Martin Odegaard’s shot over the crossbar while Arsenal sought a decisive goal, but Buendia snatched the victory dramatically by curling it in after Arsenal’s failure to clear.
Saturday’s game marked just the fourth occasion since the beginning of the 2022-23 season that Arsenal commenced a league match absent Saliba or Gabriel.
Emery brings Villa to Basel for the Europa League on Thursday, followed by a visit to struggling West Ham in the Premier League on December 14.
Arsenal heads to Club Brugge for the Champions League on Wednesday and welcomes the winless Wolves in the Premier League on December 13.
