Goals from Romelu Lukaku and Nemanja Matic helped Manchester United beat Brighton 2-0.
Nemanja Matic's late thunderbolt capped a dramatic 3-2 win for Manchester United at Crystal Palace.
It is the second time United manager Jose Mourinho has invested in the 28-year-old's talents having brought him back to Chelsea in 2014 after a successful spell with Benfica.
Manchester United have yet to officially confirm the signing, but reports that a deal was imminent came after a picture of Nemanja Matic in the club's training kit was leaked on social media.
The win over Middlesbrough left Chelsea seven points clear of Tottenham Hotspur at the summit and means they will be crowned Premier League champions for the second time in three seasons if they win at West Bromwich Albion on Friday.
Nemanja Matic's thunderous long-range effort sealed a final date for Chelsea against Arsenal or Manchester City, who meet in the second FA Cup semi-final on Sunday.
Chelsea F.C. manager Jose Mourinho insisted that he would not ask owner Roman Abramovich and the Chelsea board to sanction the acquisition of fresh faces once the transfer window opens in January.
Chelsea F.C. had drawn Schalke in the Champions League opener and were guilty of squandering several chances against Sporting Lisbon as well.