London: Chelsea midfielder Willian broke through Everton's resistance with a late goal to clinch a 1-0 over the 10-man visitors on Wednesday and preserve the team's seven-point lead at the top of the Premier League.
Willian's 89th-minute strike from outside the penalty area flew past goalkeeper Tim Howard. It came shortly after Everton midfielder Gareth Barry was sent off for tripping Willian and receiving a second yellow card.
"The red card gave an unfair momentum to the home side which allows them to score," Everton manager Roberto Martinez said.
Martinez was particularly unhappy that in the melee that led to Barry's dismissal, Chelsea defender Branislav Ivanovic was not sent off for an apparent attempted headbutt on James McCarthy.
"That shouldn't be allowed," Martinez said. "He grabs James McCarthy around his neck in a very forceful manner and then he puts his head against him when James McCarthy never reacted. If you want to be that fair with the law, it's a red card."
But Chelsea manager JoseMourinho told BT Sport television: "Did Branislav Ivanovic go in with his head? Don't make me laugh. Don't make me laugh."
Incensed last month by striker Diego Costa being retrospectively banned for stamping, Mourinho refused to discuss the Ivanovic incident in the post-match media conference, responding to a question by threatening to walk out.
"I'm tired of stories and I'm never tired of football," Mourinho said before adding, "I am concerned with my reaction because one more question and I leave."
Winning was all the more important for Chelsea given City, which is second in the table, routed Stoke 4-1 at the same time.
"I don't remember a team being champions without a couple of victories in the last minute," Mourinho said.
"It was a very difficult match, a different Everton which is a compliment not a critic. Very well organized defensively."
Chelsea had been repeatedly frustrated by Howard on the American's return to action after almost seven weeks out with a calf injury, including tipping over Willian's first-half shot.
After the break Howard blocked Eden Hazard's effort from a tight angle, tipped Nemanja Matic's free kick clear and produced a low diving save to thwart Willian.
Chelsea manager Jose Mourinho used the game to rotate the squad, with goalkeeper Petr Cech coming in for Thibaut Courtois, who was rested.
There was an early block by Cech's left boot to keep out Romelu Lukaku's shot and a quick reaction save in the second half to thwart a close-range shot form the former Chelsea striker.
"He touched the ball twice," Mourinho said. "He was a spectator but in the first half a very good save and in the second half a super save."
Everton has now won just once in nine league matches and sits 12th in the standings.
