|First one-day international, Southampton|
|Pakistan 260-6 (50 overs): Azhar 82, Sarfraz 55|
|England 194-3 (34.3 overs): Roy 65, Root 61|
|England won by 44 runs (DLS method)|
England coasted to a 44-run win over Pakistan in a rain-affected first one-day international in Southampton.
Superb death bowling after a rain break kept Pakistan to 260-6, despite 82 from Azhar Ali and Sarfraz Ahmed's 55.
Jason Roy made 65 and Joe Root 61 in a second-wicket stand of 89 before the weather intervened to reduce England's target to 252 from 48 overs.
Three balls after the restart, on 34.3 overs, more rain ended the match with England well ahead on the DLS method.
After a fluctuating, evenly contested Test series was drawn 2-2, this comfortable victory gives England a 10-8 lead in the 'Super Series', where points awarded for results across all three formats.
Not only does it give the hosts a ninth victory in 10 one-dayers against Pakistan, it also ends a run of five ODI defeats in Southampton.
The next game in the five-match series is at Lord's on Saturday.
England use their good fortune
For all of England's dominance, they were aided by two bits of fortune.
The first came when Babar Azam, who made 40, was given out lbw off Adil Rashid despite getting an inside edge, with Pakistan's review already used by Sharjeel Khan after a blatant nick behind off Mark Wood.
Second was a rain break that arrived in the 43rd over, stalling Pakistan's momentum.
Before that Sarfraz added 65 with Azhar, who was dropped twice on nine - a simple chance to Alex Hales at gully and a very difficult tickle down the leg side to diving wicketkeeper Jos Buttler.
Sarfraz's partnership of 46 with Shoaib Malik was interrupted by the weather, with Shoaib caught at mid-off from the bowling of Liam Plunkett in the over after the restart.
From there the pacy Wood, impressing in his first international since October because of ankle surgery, the increasingly dependable Chris Woakes and Plunkett, who improved after a poor start, restricted Pakistan to only 40 runs in the last seven overs.
Roy and Root lead the chase
On a perfect batting surface, Pakistan's total never looked like being enough and the decision to omit leg-spinner Yasir Shah left an attack short on ideas.
Roy, who needed treatment for what seemed to be a spell of dizziness, scored with typical freedom, playing some extraordinary straight-batted drives through the leg side and one sweep for six off the spin of Imad Wasim.
After Hales guided Umar Gul to slip, some excellent running was a feature of Roy's stand with Root, who swept and drove his way to a 23rd score of 50 or more in ODIs, coming at a rate of one every three innings.
Both feel needlessly - Roy well caught at long-off by Azam from the spin of Mohammad Nawaz and Root run out by Azhar's direct hit when called through for a short single by Eoin Morgan.
Still, England were accelerating once more through Morgan and Ben Stokes, playing as a specialist batsman on his return after a calf injury, when the rain first delayed the inevitable, then confirmed their victory.
Where's Yasir Shah? - what they said
Former England captain Michael Vaughan: "We talk a lot about luck in cricket, there certainly are things that are out of your control. The rain really did affect Pakistan, it might have cost them 20 or 30 runs."
Ex-England spinner Phil Tufnell: "Where's Yasir Shah? Where's the mystery bowler? Two or three of his special deliveries to new batsmen and you don't know what might have happened."
Man of the match Jason Roy: "It sets a nice benchmark but again we are looking to push on from this. I'm feeling good and trusting my training. Hopefully I can put in another performance for the guys on Saturday."