Man United 2 Chelsea 0
Chelsea lost 2-0 to Jose Mourinho's Manchester United, but remain four points ahead at the top of the table.
It was always going to be a tough fixture for Antonio Conte's side, who will look to regroup for next weekend's FA Cup semi-final against Tottenham Hotspur.
With Marcos Alonso injured, Kurt Zouma came into the back three, while Cesar Azpilicueta moved up into the wing-back position.
Goalkeeper Thibaut Courtois was also out, but Conte had a ready replacement in Asmir Begovic. Captain Gary Cahill joined David Luiz and Zouma in defence, while Victor Moses was on the right wing.
N'Golo Kante, who is up for the PFA Player of the Year award, joined Nemanja Matic in central defence. Eden Hazard, another Player of the Year nominee, was part of a front three with Pedro and Diego Costa.
United, who drew in Europe on Thursday, had less rest than the Blues coming into the match, but were still out of the gates quickly.
Their early goal was scored on a counter-attack. Ander Herrera started the move with a long ball. Marcus Rashford got behind the Chelsea defence and scored.
Chelsea had very few chances in the first half, and so when United went two goals ahead soon after the break, it made things that much harder.
Antonio Conte reacted, bringing on Cesc Fabregas for Victor Moses and going into a 4-3-3. Fabregas almost had an instant impact with a clever free-kick, but United goalkeeper David De Gea was quickest.
It was the Blues' first loss to a team outside London this season, and the first loss to United since 2012.