Aston Villa closed to within two points of the top of the Premier League as John McGinn's goal beat title rivals Arsenal 1-0 on Saturday.
Unai Emery's men have now won 15 consecutive Premier Leagues at Villa Park and back-to-back victories over Manchester City and the Gunners have sparked hopes of an unexpected challenge for their first title since 1981.
The only goal came after just six minutes when Villa captain McGinn span onto Leon Bailey's cross and fired into the top corner.
Arsenal's second league defeat of the season leaves Mikel Arteta's men one point behind Liverpool, who went top with a controversial 2-1 win at Crystal Palace earlier on Saturday.
Victory was sweet for Emery, who was sacked by Arsenal four years ago.
The Spaniard has made a remarkable impact in just over a year at Villa on his return to England.
Arsenal's ascent to the top of the table prior to this weekend has been built on a series of vital late goals.
And the visitors nearly snatched a point in stoppage time as Kai Havertz forced the ball home in a goalmouth scramble, but the German international handled before prodding in at the back post.