"It's incredible, honestly I can't believe it," said the 21-year-old, a £58million signing from Borussia Dortmund.

"The goals were amazing. It's tough to say which was my favourite. The header was cool but I think I'd have to go with the first one, the left foot, I don't know why.

"It's actually my first professional hat-trick so I nearly forgot the match ball, luckily my team-mates helped me out."

It was a seventh straight win in all competitions for Lampard's youthful side, made all the more special for the manager as it came on the back of arguably their best result yet – a 1-0 Champions League win over Ajax in Amsterdam on Wednesday.

"It's really pleasing because it's a worry," said Lampard, who included Pulisic ahead of Callum Hudson-Odoi in the only change from midweek. "You travel back, you're aware the other team doesn't have that situation.

"That was a really taxing game, it was our toughest physical game of the year, so credit to the medical staff and everyone that works around the players.

"They put a lot of hours in, and in the last two or three days, the players themselves have been professional about how they have recovered and picked themselves up to come to Burnley."

The only negative for Chelsea were two late goals for Burnley as Jay Rodriguez hit a stunning strike in the 86th minute before Dwight McNeil found the net in stoppage time, suggesting their defensive worries are not yet over.

"We knew it would be a tough match," Lampard added. "It's easy to take the small gloss off it with two goals late on, but it doesn't take any gloss off for me. For 95 per cent of the game we played some outstanding football at a really tough place to play, that's what made me very happy."

It was a frustrating night for Burnley on the occasion of their 200th Premier League game as first-half errors from Matthew Lowton and James Tarkowski were punished by Pulisic while Ashley Barnes could not take a number of opportunities that came his way.

"It was an odd night in that I don't think there was too much in the game, especially in the first half," manager Sean Dyche said.

"We've created some good chances, but we ended up 2-0 down when mistakes were punished.

"It's poor from us for giving the ball away in those positions, and credit to them for taking those chances, but you come in 2-0 down and scratching your head.

"Then we started the second half quite bright and took the game on again, but we gave away a third and then it's really tough.

"At four it certainly didn't feel like a 0-4 game, because we created some really good chances and that's pleasing."