Chelsea 1, Manchester United 0
Manchester United manager Jose Mourinho hit back at Chelsea fans who taunted him with cries of "Judas" as his latest return to Stamford Bridge ended on another sour note.
Midfielder N'Golo Kante fired Chelsea into a Wembley FA Cup semi-final against Tottenham with only his second goal for the club, as the Blues ground down a United team forced to play with 10 men for 55 minutes.
Mourinho and Chelsea opposite number Antonio Conte clashed on the touchline for the second time in as many meetings over the dismissal of Ander Herrera, while the United boss responded to abuse from a vocal minority of home fans by holding up three fingers - a reminder of his contribution to the club's Premier League title tally.
"They can call me what they want, I'm a professional," he said. "I defend my club and until the moment they have a manager that wins four Premier Leagues for them, I'm the No1. When they have somebody who wins four Premier Leagues for them, I am No2. But until then, Judas is No1."
Conte conceded that in-form Tottenham represented perhaps the hardest possible draw - Arsenal face Manchester City in the other tie - and said the decision to send off Herrera stemmed from United's systematic targeting of Eden Hazard.
"My players want to play football. For 25 minutes it was impossible for Hazard to play football because he received kicks. No one can say that this did not happen," he said.
"It's not football for me. I think everyone saw this. But I think sometimes when you play against players with great talent you try to intimidate these players and I think the referee must protect this type of player."
United, who had lost just once in 28 games but were shorn of forwards Zlatan Ibrahimovic, Anthony Martial and Wayne Rooney, ambushed Chelsea with a feisty start although they failed to capitalise, with Marcos Rojo wasting a free header at a corner and Henrikh Mkhitaryan dragging a shot wide.
The visitors were indebted to David de Gea for a fingertip save from Eden Hazard in the 16th minute, after the Chelsea No10 had left Chris Smalling for dead with a sublime turn, and the United goalkeeper excelled himself again seconds later when he kept out Gary Cahill's close-range shot from the resulting corner.
A simmering contest boiled over on 35 minutes when Michael Oliver showed Herrera a second yellow card in the space of a quarter of an hour, for a trip on Hazard, leading to the first touchline confrontation of the evening between Conte and Mourinho, who saw his United team beaten 4-0 here in October.
Herrera's second dismissal of the season only strengthened Chelsea's hold on the game, which Kante cemented shortly after half-time when he fired low past De Gea from the edge of the penalty area after Paul Pogba had afforded his erstwhile France midfield colleague too much room.
Rashford conjured United's only clear chance on 59 minutes when David Luiz misjudged a high ball and the England striker turned Gary Cahill inside out, only to be denied by a star-jumping Thibaut Courtois.
Costa headed wide unchallenged when he should have added Chelsea's second, while Willian skimmed the roofof the net, forced De Gea to beat away a rising drive and then narrowly missed Costa with a low cross in a whirlwind few minutes.
United's last chance to equalise fell to Pogba eight minutes from time, but he dragged a left-footed shot wide from the edge of the box, while De Gea kept the deficit minimal in the dying seconds when he saved from substitute Cesc Fabregas.