Player of the match Mahmood took an ODI best 4-42 as Pakistan were skittled out for just 141 with more than 14 overs left to bat.

England, the reigning 50-over world champions, made 142-1 to go 1-0 up in a three-match series ahead of Saturday's clash at Lord's.

Dawid Malan was 68 not out after a run-a-ball fifty.

Together with Test batsman Zak Crawley (58 not out), one of five ODI debutants in the England team, he shared an unbroken stand of 120 as a match scheduled for 100 overs finished in a mere 67.1.

England were fielding a completely changed XI from their previous ODI -- the first time this had happened to any side in the 50-year history of the format -- after a Covid-19 outbreak within their existing squad during a recent 2-0 series win at home to Sri Lanka required all 16 players originally selected to play against Pakistan to self-isolate.

In addition, injuries to fast bowlers Jofra Archer and Olly Stone and wicketkeeper-batsman Jos Buttler meant they were effectively without two first-choice XIs.

- 'Clinical' -

Yet their 'C team' dominated from the moment Mahmood took a wicket with the first ball of the match -- and then dismissed Pakistan captain Babar Azam, the world's top-ranked ODI batsman, for a duck with the third ball.

"It was a very clinical performance, when you get opposition four down early on then you're ahead in the game," said stand-in England captain Ben Stokes at the presentation ceremony.

"When you get a new group together you're striving for that first real team performance. We didn't get put under pressure today, I have no doubt we will at some point."

Mahmood added: "As a team we want to win games, and as players you want to contribute to those wins."

Azam paid tribute to England's makeshift attack by saying: "We were a bit loose with the bat, and that's why we didn't get a big total, but credit to the England bowlers."

Such was England's command, Stokes bowled just one over despite the World Cup-winner being the most experienced member of the attack.