England beat Pakistan by 44 runs on the Duckworth/Lewis scoring method in a rain-affected first One-Day International in Southampton on Wednesday.
Pakistan made 260 for six in their 50 overs and England moved on to 194 for three in 34.3 overs, Jason Roy making 65 and Joe Root 61, before rain brought a premature end to the match.
Pakistan captain Azhar Ali, who won the toss, hit 82 to lead his team to a below-par total in bright sunshine and ideal batting conditions.
Azhar started slowly but increased the tempo to strike nine fours before top-edging leg-spinner Adil Rashid to Moeen Ali at short fine leg.
Babar Azam scored 40 and Sarfraz Ahmed 55 but the touring side never really broke the shackles imposed by a disciplined England attack in which Rashid was the most successful bowler with figures of 2-51.
England lost Alex Hales for seven but Roy flayed six fours and a six and shared a second-wicket partnership of 89 with Root.
Roy was caught on the long-off boundary off Mohammad Nawaz and Root was run out after being called through for an impossible single by captain Eoin Morgan but England were always ahead of the required run rate.
Morgan finished on 33 not out with Ben Stokes on 15. The second game in the five-match series is at Lord's on Saturday.
Azhar Ali c Ali b Rashid 82
Sharjeel Khan c Buttler b Wood 16
Mohammad Hafeez c Hales b Root 11
Babar Azam lbw b Rashid 40
Sarfraz Ahmed c Wood b Woakes 55
Shoaib Malik c Rashid b Plunkett 17
Mohammad Nawaz not out 17
Imad Wasim not out 17
Extras (lb1, w4) 5
Total (6 wkts, 50 overs) 260
Fall of wickets: 1-25 (Sharjeel), 2-52 (Hafeez), 3-113 (Babar), 4-178 (Azhar), 5-224 (Malik), 6-226 (Ahmed)
Bowling: Woakes 10-2-43-1; Wood 10-0-57-1 (3w); Plunkett 10-0-52-1; Root 4-0-26-1 (1w); Ali 7-0-30-0; Rashid 9-0-51-2
Jason Roy c Babar Azam b Mohammd Nawaz 65
Alex Hales c Mohammad Hafeez b Umar Gul 7
Joe Root run out (Azhar Ali) 61
Eoin Morgan not out 33
Ben Stokes not out 15
Extras (lb6, w7) 13
Total (3 wkts, 34.3 overs) 194
Fall of wickets: 1-27 (Hales), 2-116 (Roy), 3-158 (Root)
Bowling: Wasim 5-0-23-0; Amir 6-0-33-0; Gul 6-0-46-1 (2w); Riaz 6-0-30-0 (5w); Nawaz 6.3-0-31-1; Malik 5-0-25-0.