England 373-3: Buttler hits England's second-fastest century in ODI cricket - off 50 balls
Morgan adds 71 off 48 balls, Roy makes 87 on return from injury
Fakhar hammers 138 off 106 to give Pakistan chance of victory
Willey impresses with ball - taking 2-57
Eng 115-0
If his big hitting wasn't tough enough to counter, Jonny Bairstow is also a superb runner between the wickets and turns one into two with aplomb here.
Shaheen strays down the leg side and Bairstow clips another two down to fine leg.
England on Nelson - and they get off it in fine style as Bairstow whips a short ball inside fine leg for four.
That's a terrific fifty for the Yorkshireman. A superb knock so far - can he convert?
Image source, Getty ImagesPakistan's pre-match huddle was dominated by the towering presence of opening bowler Shaheen Afridi.
He's a big lad and he's coming back into the attack.
Cries of "catch it" but Jason Roy has cracked it just wide of long-off to pick up four.
Yasir Shah then beats the edge of the bat as Roy tries to cut. Better from the leg-spinner.
Image source, Rex FeaturesEngland's ODI statistical records should probably just start in 2015.
This team are playing a completely different sport to England ODI sides of old.
Andy Zaltzman
Test Match Special statistician
This is the sixth century opening partnership for Jonny Bairstow and Jason Roy in the 25 innings they've opened together. That's an England record.
Image source, Getty ImagesRoy 52, Bairstow 43
Imad Wasim continues to offer much better control than the rest of the Pakistan bowlers.
England can only tap his around for ones and twos but accumulate nicely to pass 100 in the 17th over.
The mad thing is, this isn't even that close to how good Jason Roy and Jonny Bairstow can play. Perhaps seven out of 10 stuff so far.
This raced off the bat, the fielder in the deep didn't have a chance.
Andy Zaltzman
Test Match Special statistician
This is Jason Roy's 20th half-century in one-day cricket, seven of which he has turned into hundreds.
It is his second in his past 10 innings and his fourth score of 50 or more against Pakistan.
Michael Vaughan
Ex-England captain on TMS
Jonny Bairstow won't miss out on that - that was a pie from Yasir Shah.
Jonny Bairstow absolutely clatters a four through the leg side after Yasir Shah serves up a gift.
England are more than happy to get after the leg-spinner already.
And after a slightly slow start, the hosts are quickly up to six an over.
Time for a drink.
Michael Vaughan
Ex-England captain on TMS
Roy has kept the strike really well - he's faced 25 more deliveries than Jonny Bairstow.
Simon Mann
TMS commentator
This is a confidence-boosting comeback from Jason Roy after barely playing this season with a back and a hamstring problem.
Image source, Getty ImagesEng 92-0
Jason Roy reverse-sweeps emphatically for four before clipping a single to bring up a fine fifty.
Slow by his standards - off 60 balls - but he's had to feel his way back into his strokes on his return from a back injury.
Leg-spinner Yasir Shah is into the attack. He's not in Pakistan's 15-man preliminary World Cup squad so needs a good match here.
A fine Test bowler, he struggles in ODIs because he doesn't often challenge both edges of the bat, unlike Adil Rashid, for example, who has a much better googly.
Stephan Shemilt
BBC Sport at The Ageas Bowl
In and around The Oval on Wednesday, you'd have been hard-pressed to know that the World Cup was coming. It's the same in Southampton. Nothing in the city, nothing in the ground. No flags, banners, adverts or mentions on the big screen. Strange.
Roy 44, Bairstow 33
Two chances, no wicket, but another fine over from Imad Wasim, conceding just three from it.
And Michael Vaughan is spot on.
Impact in line, hitting in line but the ball didn't spin back at all and so was umpire's call on clipping leg stump.
Umpire Tim Robinson then makes the signal to overturn his decision before remembering he did give it not out on the field. On we go...
Michael Vaughan
Ex-England captain on TMS
The problem with Imad is he's not a spinner that spins the ball - it's always angling in. So unless it's hit Bairstow on middle or off stump, you'd think at best it's going to be umpire's call.
Imad Wasim gets one through on to Jonny Bairstow's pads and really, really likes it.
Massive appeal. Not given.
Safaraz Ahmed likes it too and send it upstairs.
Going down leg?
Imad actually broke the bails with his hands as he tried to lift them over the stumps to catch the throw.
He then failed to gather the throw and could have had a chance of removing a stump had he done so.
Poor technique.
Image source, Getty Images