Two goals from substitute Ollie Watkins stunned Chelsea on Saturday, after Aston Villa soaked up intense pressure before coming from behind to snatch a 2-1 away win in the Premier League.
It was the 11th successive win in all competitions for the Birmingham side, who are proving title contenders and lie in third, just three points behind leaders Arsenal in the table.
They are back in London on Tuesday for a pivotal clash with Arsenal.
Chelsea had been in total control when captain Reece James's 37th-minute corner swung towards a crowded goalmouth and clipped Joao Pedro's leg before crossing the line to put the home side 1-0 up.
They had squandered a hatful of chances, with James, Enzo Fernandez, Alejandro Garnacho and Cole Palmer shooting wide or high and Villa goalkeeper Emiliano Martinez was forced into action to save from Palmer and Joao Pedro.
Halftime stats showed Chelsea had 28 touches in the opposition box to Villa's three and more than 71% possession.
However, Unai Emery's substitutions shortly before the hour mark turned the match on its head, the visitors reacting with new energy and momentum.
In the 63rd minute when on the counter, Watkins, who had been on the pitch only four minutes, outmuscled defender Trevoh Chalobah and scored from a rebound off home goalkeeper Robert Sanchez.
And Watkins completed the comeback in the 84th minute, heading home a Youri Tielemans corner.
"Amazing win. Personally, for me, to come off the bench and score goals is amazing," Watkins told Sky Sports.
"Emery changed (the system), because Chelsea were playing man-to-man. We had an extra body up there. Tactical genius, I'd say."
The result meant Aston Villa equalled the all-time club record of 11 consecutive wins, set in both 1897 and 1914.
Their rise this season is remarkable after they failed to win any of their first five games.
They have earned a series of comeback away victories - against Leeds United, going 1-0 down and winning 2-1, Brighton & Hove Albion where they were 2-0 down and came back to win 4-3 and West Ham United where they won 3-2 after being 2-1 down.
For Chelsea, it is one win in six Premier League games and they lie 10 points behind Villa, in fifth place.
