Ben Duckett struck a sparkling 167 off 132 balls at the Gaddafi Stadium as England finally claimed a win in their tri-series in Pakistan, beating Sri Lanka by 55 runs in a dead rubber.

It was Duckett's second hundred in succession and his third in four innings in Lahore, a ground where he also made his previous ODI best.

Tom Banton contributed 74 at the top of the order as England piled up 386 for five.

The victory was England's first in seven ODIs in Pakistan, after they had chances to win all three previous matches and squandered seemingly unlosable positions in their last two.

England had failed to defend 429 against the same opponents last Thursday, and Pavan Rathnayake's second successive century against Harry Brook's side might have brought on a case of deja vu.

But Rathnayake lacked support from his middle-order colleagues.

When he sliced a sweep off Liam Dawson to depart for a majestic 118 off 77 balls, the eighth wicket to fall, the writing was on the wall.

Sri Lanka were all out for 331.

While their bid to simulate tournament conditions for next year's World Cup fell flat, England at least head to Australia for a white-ball series with a morale-boosting win.

Sent in after losing the toss, England's openers got off to a flyer on Thursday with a 163-run stand.

Banton's slash at his first delivery bounced in front of first slip, but England's openers soon got on top from the moment Duckett clipped off his legs then pulled Dilshan Madushanka for back-to-back fours in the second over.

Banton was fluent off the back foot and charged slow left-armer Dunith Wellalage and part-timer Janith Liyanage for sixes down the ground.

Duckett especially relied on crisp timing and methodical placement to stockpile boundaries. They each went to their fifties at better than a run-a-ball.

Banton dragged Dasun Shanaka's off-cutter on to his stumps for 74, but Duckett soon brought up his sixth ODI century off just 89 deliveries.

Brook promoted himself to number three and took 12 singles from his first 22 balls following his elevation.

Although he belted two fours and two sixes off his next four deliveries, he botched an attempted scoop to give Asitha Fernando a return catch and depart for 44.

Duckett took 29 balls to go from 100 to 150 and went past his previous ODI high of 165, which came at this ground in last year's Champions Trophy, before failing to beat the short fine-leg fielder on the sweep.

Will Jacks, Jordan Cox and Sam Curran were all shuffled up the order, relegating Joe Root, and they all contributed decent cameos.

England were soon under the pump with the ball despite Sonny Baker bowling Kamindu Mendis through the gate.

Baker dropped Avishka Fernando on five while Kusal Mendis had his bat broken, but the Sri Lanka pair put on 84 without looking troubled. Fernando took 13 off Henry Crocombe's first over but holed out for 48.

Kusal, run-out without facing a ball during Sri Lanka's run-chase last week, showed off his array of flicks, pulls and drives to thump five sixes and eight fours.

He under-edged down the leg-side for 89 as Root burgled a wicket in his first over. Shanaka was given lbw on review after missing a swipe off Liam Dawson.

Although Liyanage belted three sixes, he tamely chipped to Brook to give Baker his second wicket.

Rathnayake, though, was proficient on both sides of the wicket and, with the dew descending around the halfway point of Sri Lanka's innings, continued to be a thorn in England's side a week after his century against them.

England failed to review when Sahan Arachchige gloved down the leg-side off Baker, not even appealing.

Curran could not hold on when Rathnayake drilled a full toss back to him on 98, but when Crocombe was reintroduced, Arachchige shovelled to Brook at long-off.

Wellalage was run-out after a mix-up with Rathnayake, who could have been left stranded had Curran whipped off the bails sooner, and England completed their shortly afterwards.