Manchester United capitalised on Robert Sanchez's fifth-minute red card to secure a crucial victory over Chelsea in torrential rain at Old Trafford.

The first match in Premier League history to see two or more goals, red cards and substitutions in the first half was settled by goals from United skipper Bruno Fernandes and Casemiro, who was the other player sent off before the break.

It was Sanchez's dismissal that set the course of the game though.

The Spain international raced from his goal to meet Bryan Mbeumo as the striker ran beyond the Chelsea defence.

Sanchez then upended the forward outside his area rather than allow him past to tap the ball into an empty net.

Enzo Maresca's response to the red card was to take off both Pedro Neto and Estevao Willian and, as Cole Palmer had to be replaced after suffering a recurrence of a groin injury, Chelsea had lost three attacking players in the space of 20 minutes.

Trevor Chalobah pulled one back for Chelsea with a header 10 minutes from time but United kept their nerves at bay to make it to the final whistle with their lead intact.

The victory was United's second of the season and came in front of minority owner Sir Jim Ratcliffe, who gave head coach Ruben Amorim assurances over his future 48 hours earlier.

It also means Chelsea have still not won at Old Trafford since 2013, when Sir Alex Ferguson was United manager.