Before Aston Villa’s goal came, Chelsea were on top and looking far the likelier to score. Nicolas Jackson and Raheem Sterling were both denied one-on-one by excellent Emiliano Martinez saves while Enzo Fernandez sliced another glorious opportunity wide.
Chelsea were equally indebted to their goalkeeper, Robert Sanchez, who made a pair of flying fingertip saves to thwart beautifully-struck volleys by Lucas Digne and Nicolo Zaniolo.
However, a pitch-side VAR decision just before the hour mark turned proceedings against them. Malo Gusto had slid in on Lucas Digne and caught the defender on the ankle, and a yellow card was quickly upgraded to red for dangerous play.
The sending off did not drastically alter the course of things at first, Chelsea’s pressure on Villa’s defence remained. Yet it was ultimately to be their undoing.
There seemed to be little on when Villa won the ball back high in the Chelsea half. Moussa Diaby dashed into the space left by Gusto’s departure, and in a flash, he fed Ollie Watkins.
Levi Colwill seemed to have things under control when he slid to block Watkins’ initial shot, but before he could recover and clear, the Villa striker had taken up the ball and lashed his second effort past Sanchez from an angle and in off the far post.
Aston Villa ran off as winners of the match after holding on to the goal scored. The win pushed them to the sixth spot on the Premier League table, while Chelsea who have failed to score for a third successive game moved to the 14th spot.
The Blues have just five points from their opening six games and their woes pre-date Pochettino’s appointment, with only two wins and 11 goals in their past 14 home league matches.