United had Daniel James sent off for a dangerous high tackle on Mateo Kovacic, who had to be replaced. They later became the first team to ever receive 100 yellow or red cards in a Premier League season.
Christian Pulisic slotted Mount’s pass into the bottom corner from 20 yards.
Romelu Lukaku – who earlier had a goal disallowed – scored the third goal that the Blues’ dominance deserved as he took his time to hold off three defenders and smash home.
Leeds offered very little and their hopes of staying up are out of their hands. They are behind 17th-placed Burnley on goal difference but the Clarets have a game in hand.
Chelsea only need to beat one of Leicester or Watford – or hope Tottenham do not win all three remaining games – to clinch a place in next season’s Champions League. But for now their focus turns to Saturday’s FA Cup final against Liverpool.