Chelsea scored two late goals as Thomas Tuchel's side bounced back from consecutive defeats to beat Southampton and move top of the Premier League.
Timo Werner and Ben Chilwell struck in the final six minutes after Saints had been reduced to 10 men following the dismissal of captain James Ward-Prowse for a poor challenge on Jorginho.
Academy product Trevoh Chalobah put the hosts ahead after nine minutes, swooping at the back post to head in his second of the season after Ruben Loftus-Cheek flicked on Chilwell's corner.
A dominant Chelsea had the ball in the net on two further occasions in the first half, however Romelu Lukaku was flagged offside and Werner's header was ruled out following a foul by Cesar Azpilicueta on Kyle Walker-Peters in the build-up.