Pulisic, who made his first league start since Aug. 31, was on target twice in the first half and made it 3-0 with a sublime header after the break before Willian got the fourth, stretching Chelsea's streak to seven successive wins in all competitions.

The win left Chelsea fourth on 20 points from 10 games while Burnley are 11th on 12 points after a tepid performance in their 200th Premier League fixture and 100th at Turf Moor.

Chelsea manager Frank Lampard was delighted with his team's performance and also elaborated on why he had deliberately kept Pulisic on the fringes in the early stages of the season.

"This is a really tough place to go and the way we controlled the game, our midfield combinations and movement, was beautiful to watch," Lampard told Sky Sports.

"(Pulisic) had a week's break this summer. He arrived for a big price and wanted to come straight back in but at the same time why am I going to throw him in?

"So I have to do it in the right way and get the best out of him. I’m delighted for him."

The 21-year-old Pulisic, who became the youngest Chelsea player to score a hat-trick, fired the visitors ahead in the 21st minute after shaking off two defenders and doubled their advantage with a deflected shot on the stroke of halftime.

The U.S. international capped a stellar performance in the 56th when he headed past keeper Nick Pope with his back to goal before the lively Willian fired an arrowed shot into the far corner from 12 metres after neat footwork in the area.

Chelsea then had a penalty rescinded after a VAR check showed Callum Hudson-Odoi had not been fouled and instead of getting a spot-kick the substitute was booked by Michael Oliver.

Burnley gave their disappointed fans something to cheer with two late goals as Jay Rodriguez rifled in a piledriver from 25 metres in the 86th minute and Dwight McNeil drove home a deflected effort three minutes later.

Though unhappy with the lapse of concentration in the closing stages, Lampard refused to chastise his team for conceding twice in quick succession.

"I will be the first to criticise sloppy goals, but not tonight because of the way they played, there were so many great things to admire.

"I’m not letting that in the dressing room tonight, we came to a really tough place and won comfortably."