Kurt Zouma grabbed his first goal for Chelsea as they defeated rivals Arsenal, who ended the game with nine men, 2-0 at Stamford Bridge this afternoon.
The first half was an on-and-off affair, with Theo Walcott coming close to opening the scoring for Arsenal but the striker was well pressured by Asmir Begovic.
Pedro and Diego Costa troubled Petr Cech on his return to Stamford Bridge, before Gabriel was shown a red card for an off-the-ball incident that saw him walk over to Costa and lash out at him with his foot.
Zouma then gave Chelsea the lead after the break, heading in a deep Cesc Fabregas free kick at the back post.
Oscar continued with his impressive display for Chelsea with a couple of dipping shots, as Costa also came close to doubling Chelsea's lead.
Santi Cazorla received a second yellow card for a late tackle on Fabregas to take Arsenal down to nine men, and Eden Hazard took full advantage with a shot that took a wicked deflection off substitute Calum Chambers to settle in the net behind Cech.
Aaron Ramsey had a chance to grab a goal back at the end but the onrushing Begovic did well to stop the Gunners gaining a consolation.
It is a much-needed victory for Mourinho's men who move up to 10th place in the Premier League while Arsenal remain in fourth.