Chelsea scored three second-half goals to win at Everton and re-establish a seven-point lead over Tottenham Hotspur, who take on their North London rivals Arsenal later on Sunday.
The Premier League leaders stepped up the pace after a tight first half to end up in full control at Goodison Park.
Everton provided the first threat early on when Dominic Calvert-Lewin's effort hit the foot of the post, but Chelsea soon hit back and Gary Cahill tried his luck from long range to force Maarten Stekelenburg into an uncertain save.
Eden Hazard then zipped away from defenders down the left before firing in an effort that deflected up into the air and was cleared.
The Belgium international was then found by Diego Costa and took the ball around Stekelenburg only to find the side-netting from a tight angle.
Young home midfielder Tom Davies then produced a strong sliding challenge on Costa as he shaped to shoot after being found by Hazard.
It was an attacking start and both sides came close within moments of each other around the quarter-hour mark, Nemanja Matic drifting into space to hit a low shot that was saved by Stekelenburg.
At the other end, Romelu Lukaku -- reported to be a summer transfer target for his old club Chelsea -- fizzed an effort wide.
Costa should then have given Chelsea the lead after David Luiz found him with a long pass, but he smacked his effort high into the Gwladys Street End.
Luiz was in action at the other end as Lukaku tried to break free, preventing him from getting a clean strike at goal, and with five minutes left until the break Ross Barkley saw a free kick from 25 yards cannon to safety.
In added time at the end of the first half, Matic flicked on a corner but no colleague was able to reach the ball.
Chelsea stepped up the pace in the opening moments of the second half and a driven Victor Moses cross was only inches away from Costa as it deflected towards him.
Costa was booked for fouling Stekelenberg after a short Phil Jagielka backpass had put Everton in trouble -- but they were soon asking the visitors questions at the other end as an Enner Valencia effort was deflected past the post.
Moments later, Valencia got away down the left and his low cross was held by Courtois, and then Barkley waited too long to find a pass to Lukaku as the striker sped through the middle.
But Chelsea broke the deadlock in spectacular style with 66 minutes on the clock as Pedro picked up possession, turned into space and fired an outstanding finish into the top corner from 20 yards.
And with 11 minutes remaining, the Londoners made sure of the points as a low Hazard free kick was parried by Stekelenburg and went in off Cahill.
Chelsea made a double change soon afterwards, taking off Pedro and Luiz, who appeared to have taken a knock, and replacing them with Cesc Fabregas and Nathan Ake.
Five minutes from the end, Eden Hazard was replaced by Willian -- and the Brazilian soon added a third as he turned home a neat Fabregas cut-back.