Pulisic had yet to score for us before today but how the American, handed his first league start since August, changed that record in Lancashire!

He scored twice in the first half after carrying the ball at speed and finishing decisively with each foot. Both goals stemmed from the Blues stealing possession high up the pitch with plenty of claret shirts ahead of play.

Pulisic's and our day got even better 10 minutes after the interval as the American registered a treble for the ages with a cute header from a fine Mason Mount delivery.

Willian got in on the act shortly afterwards, firing home to round off another speedy Chelsea break. The Brazilian’s replacement Callum Hudson-Odoi thought he’d won us a penalty, but VAR overturned the decision.

Burnley, who wasted a couple of good chances when the game was more evenly balanced at 1-0, had the final say with two goals in the final five minutes. The first was a Jay Rodriguez thunderbolt from a good 30 yards, the second a deflected Dwight McNeil effort.

It spoiled our clean sheet, but not the result or the overall performance, yet another exciting display. For the first time in our history we have won four consecutive top-flight away games scoring three goals or more in each, while Lampard can celebrate a fourth straight league win for the first time in his short managerial career.

The boss made a solitary change to the side that began the midweek win against Ajax, with Pulisic coming in for Hudson-Odoi.

For Burnley, Ashley Barnes and former Blue Jack Cork returned after injury, but Chris Wood was not deemed fit enough to feature.

Aside from a Willian shot over and a nasty collision with the advertising hoardings for Kurt Zouma, the opening 10 minutes passed by with little incident. It was however immediately apparent the Blues were in for a battle, with and without the ball.

Our brightest player going forward had been Pulisic, and it was the American who opened the scoring midway through the half. It was all his own work, too, pinching possession off the dawdling Matthew Lowton and then haring goalwards. A drop of the shoulder took him past James Tarkowski, and then he arrowed a cute left-footed finish back across Nick Pope.

Burnley reacted strongly. Tomori sprinted to thwart Barnes who had got free down our left, and from the resulting corner the striker headed wide after Tarkowski had won the first header.

The Clarets kept pressing. Zouma headed another cross away as far as Pieters, whose well-struck volley deflected off Azpilicueta. The ball looked like it might loop up over Kepa, who was already moving to his left, but the keeper superbly reacted to claw it away.

It was Kepa’s opposite number Pope who was next to keep out a deflected effort. Willian’s diagonal pass found Pulisic in space, and he chested and shot in one movement, with the slightest of touches forcing Pope to adjust and palm behind.

Burnley’s best chance of the first half was not surprisingly from a set-piece, with Mee heading back across goal and Barnes nodding wide from a yard out, perhaps unsighted by the jumping Tammy Abraham in front of him.

Pulisic’s next shot was blocked by Tarkowski, who atoned for a weak clearance, and Abraham curled wide from 20 yards as the Blues enjoyed our best period of controlled possession.

It looked like we would head in at the interval 1-0 up, but Pulisic had other ideas. Willian stole possession and fed the American, who again had space to race into. Just as for the first goal he slipped past Tarkowski, and this time his right-footed drive took a significant deflection off Mee and fizzed into the bottom corner.

Lampard sent his charges out early for the second half with the intention of killing the game. That’s exactly what we did before the hour.

If Pulisic’s first two goals had all been about clever dribbling and changes of direction, his third was the perfect exponent of how to head a ball. Mount’s corner was cleared back to him, and the whipped cross that followed was superbly guided into the top corner by Pulisic, who was facing away from goal as he made contact with the ball.

Pulisic raised three fingers to the jubilant travelling support behind the goal. There was no doubt this was his day!

That goal was in the 56th minute, and with two more played it was 4-0. Abraham did well in the centre of park before moving it on to Willian. He made it look so simple, standing his defender up before shimmying and drilling a low effort beyond Pope.

We continued to show our capabilities defensively, with Tomori sprinting at full pelt to superbly thwart Rodriguez who was one on one and looked certain to score.

Reece James came on for Alonso and immediately made two blocks, and another sub, Callum Hudson-Odoi, thought he had won us a penalty, but VAR overturned the decision and the youngster was booked for simulation.

It looked like the game was winding down to a gentle conclusion, but two late Burnley goals briefly livened things up. Rodriguez’s was the best goal of the day, a stunning long-ranger that gave Kepa no chance on 85 minutes. McNeil, the hosts’ best performer, then saw his speculative shot take a nick off Tomori and fly past Kepa.

They couldn’t dampen another great day on the road for Lampard and his team, who will go for an eighth straight win against Manchester United in the Carabao Cup on Wednesday.

Chelsea (4-3-3): Kepa; Azpilicueta (c), Zouma, Tomori, Alonso (James 63); Kovacic, Jorginho, Mount; Willian (Hudson-Odoi 72), Abraham (Giroud 70), Pulisic.Unused subs Caballero, Guehi, Pedro, Batshuayi.Scorers Pulisic 21, 45, 56, Willian 58Booked Willian 53, Hudson-Odoi 77

Burnley (4-4-2): Pope; Lowton, Tarkowski, Mee (c), Pieters; Hendrick (Brady 84), Westwood, Cork, McNeil; Barnes (Vydra 63), Rodriguez.Unused subs Hart, Taylor, Bardsley, Long, Lennon.Scorers Rodriguez 86, McNeil 89Booked Hendrick 65, Pieters 67, Brady 90+2

Referee Michael OliverCrowd 20,975