Ollie Watkins emerged from the bench to spearhead a superb Aston Villa revival as they came from behind to confirm their Premier League title credentials at Chelsea with an 11th successive win in all competitions.

Chelsea deservedly led after 37 minutes when striker Joao Pedro got a vital touch in a goalmouth scramble as Villa tried to clear Reece James' corner.

Villa, seeking to equal a club record set in both September 1897 and March 1914, had been second best until manager Unai Emery made a triple substitution just before the hour, sending on Watkins, Amadou Onana and Jadon Sancho for Emiliano Buendia, John McGinn and Donyell Malen.

Emery's golden touch worked inside four minutes as Watkins raced on to Morgan Rogers' pass, Chelsea keeper Robert Sanchez saving at his feet only to see the rebound bounce in off the striker.

Villa were transformed, and it needed crucial saves by Sanchez from Ian Maatsen and Boubacar Kamara to keep Chelsea, who had dominated for so long, on level terms.

However, Chelsea were unable to keep a rampant Villa at bay, Watkins the scorer once more as he rose to power Youri Tielemans' corner past Sanchez.

Villa's win keeps them just three points behind Premier League leaders Arsenal.

Emery is currently the manager who can do no wrong, and it was his game-changing substitutions that turned this encounter on its head to confirm that Villa simply must be in the Premier League title conversation.

The Spaniard saw his side struggling to lay a glove on Chelsea, who were 1-0 ahead and comfortable, so acted decisively to set the platform for a superb victory.

He did not even wait until the hour before making the three substitutions that shifted the emphasis entirely in Villa's direction.

Watkins, in particular, was transformative, as his pace and direct running suddenly caused havoc in a Chelsea defence that had been in cruise control.

He was razor-sharp, albeit with a sprinkling of good fortune, to pounce for Villa's equaliser, then showed his power in the air to send an unstoppable header past the previously defiant Sanchez.

It came at the end of a spell of fierce Villa pressure as Chelsea wilted and Emery's side grew in stature.

Villa remain hard on the heels of pace-setters Arsenal and Manchester City, with a visit to Emirates Stadium to come in three days' time.

They will travel to north London with growing belief they can continue to shake up the established order at the top of the Premier League.

Chelsea head coach Enzo Maresca was confined to the stands serving a suspension, and this was a spectacle that would have made for disappointing viewing for the Italian.

All was progressing smoothly for an hour, Chelsea's superiority helped by a desperately lack-lustre Villa performance until opposite number Emery put his stamp on proceedings.

For all Chelsea's dominance, Villa keeper Emi Martinez was hardly over-worked, Maresca's team running out of steam badly in the final half hour.

Chelsea could have few complaints as Villa completed a dramatic turnaround to secure victory as they ran out of ideas, Cole Palmer tiring but unhappy to be replaced by Estevao with 18 minutes left.

They had no answer once Villa went ahead, failing to cause any anxious moments in the visitors' defence in the closing stages.

Chelsea drop down to fifth in the table - level on points with Manchester United - with the manner of this loss raising further questions about whether they can make a serious impact on the title race.