(CNN) -- Manchester United's post-title hangover continued on Sunday after a 1-0 defeat that kept Chelsea in pole position for England's third Champions League place next season.
Juan Mata netted the only goal in the 86th minute before the game erupted from its previous lethargy as United defender Rafael da Silva was sent off for kicking out at fellow Brazilian David Luiz. Television replays showed the Chelsea player smiling on the floor afterwards.
It was United's first red card this season, and means Rafael will miss the rest of the Premier League campaign with an automatic three-game ban.
"The referee was bought by the fact Luiz rolled about," United manager Alex Ferguson said. "He actually elbowed Rafael twice but you know what happens when a player retaliates: he's always punished more.
"Luiz made it look worse. I don't think the referee saw it, actually, and he was convinced by Luiz's reaction."
The defeat followed United's 1-1 draw with Arsenal last weekend, having previously wrapped up a record-extending 20th title with four matches to play.
"Maybe this will waken the players up," said Ferguson, ahead of next weekend's final home match this season against Swansea.
"There was no edge to our game but I think Chelsea were the better team. Training was fine this week and there was a nice edge to it, but today it was missing. It's been a long season for the players and their final really big effort was last week against Arsenal."
Mata scored his 11th league goal this season, and 19th overall, to put Chelsea a point clear of fourth-placed Arsenal and three ahead of Tottenham in fifth.
Victory in Wednesday's home clash with Spurs would virtually ensure qualification for Europe's top club competition, given their London rivals' inferior goal difference.
"If we can win we will be there, but Tottenham are a good team and it will be a final for the top four," said manager Rafael Benitez, who has guided Chelsea to two wins over United since taking charge in December.
"This game was difficult and important for us. Wednesday will be even more important as we are so close to them. Winning is crucial for us, it's even more important for them, so there will be a great atmosphere at Stamford Bridge."
Benitez is hoping to have Eden Hazard available after the Belgium playmaker missed the trip to Old Trafford due to a calf injury.
"The physios are working with him and he could be fit," said the Spaniard, whose team have played 12 games in just 37 days, reaching the final of the Europa League.
Everton's chances of playing in Europe's second-tier tournament next season suffered a blow in Sunday's 0-0 draw with Merseyside rivals Liverpool.
Manager David Moyes was angry that Sylvain Distin's second-half header was ruled out for a foul by teammate Victor Anichebe on home goalkeeper Pepe Reina.
"It was a goal. The goalkeeper runs into our player so the goal should stand," said Moyes after his sixth-placed team dropped five points behind Tottenham, having played one more game.
"If we run into the goalkeeper then give a foul for that, but he ran into us, so it was a goal."
Liverpool, in the absence of suspended top scorer Luis Suarez, stayed seventh.