Back to the cricket, Imad Wasim steps up to bowl a bit of left-arm off spin. Those extra twirls nearly earn him a wicket as a skiddy sort of delivery with a bit of extra pace and bounce goes marginally past the bat of Bairstow and the stumps.

Mickey Arthur really doesn't look pleased on the balcony. He says something in disgust then gets up for a second time and storms off somewhere. Presumably into his quiet place with a paper bag at the ready.

Irfan update number 356: He's off again. He was seen trying to run and get that hamstring firing again, but apparently it's not doing the trick. Irfan walks off shaking his head. Pakistan coach Mickey Arthur is off his chair in the balcony and runs down presumably to check on the big man.

We're into an official drinks break by the way. Got to keep that body hydrated in the sweltering heat of West Yorkshire.

Michael Vaughan
Ex-England captain on BBC Test Match Special

England have got to find a place for Jonny Bairstow in this one-day team. He's just too good. I'd be staggered if he doesn't start in the Champions Trophy games next summer.

I've lost track of how many bowling changes Pakistan have made in the last 10 or so overs. Umar Gul comes in now, with his black wrist band on the left arm. He runs in over the wicket and Bairstow comes down the track to be struck on the pad. Huge shout for lbw from Gul, who nearly got in the way of Bairstow running the single. Not given. Irfan update: He's back in and fielding. Pakistan need something to get those trumpets to sound more alive than Dracula at day time.

Image source, Reuters

Ben in Bristol

Here's some left-arm spin from Imad Wasim, who gives a few extra twirls of his bowling arm before actually, err.. bowling. England take a comfortable set of five runs without any glitzy shots. 

What's everyone predicting for this game's finish? Will Pakistan stage a dramatic fightback late on? Or will England do this with plenty of overs to spare? And what happened to all the cats following our coverage religiously?

Michael Vaughan
Ex-England captain on BBC Test Match Special

A boring England side of old would knock the ball about from here - but this lot won't. They'll continue to play the big shots.

Stokes is batting like the bowling machine has been set on 'easy'. The Durham man clobbers Nawaz high over cow corner for a massive six. He even causes some temporary anguish for a poor bloke whose priority was holding on to his drink rather than the ball. Bit of a blow to the ribs there. Stokes is not done, as he swings his bat around very next ball and thumps it to deep square leg for four.

Michael Vaughan
Ex-England captain on BBC Test Match Special

Pakistan will get a chance or two - England play so expansively, they do hit the ball in the air. But will they be good enough to grab it?

It doesn't take much for men in sombreros to get up and dance but they're all up and jigging away as Bairstow pulls Hasan to the mid-wicket boundary. He doesn't look overly pleased with the shot though, would you believe it? Mimics how he perhaps should have played it. Steady on, Jonny. They all count.

Simon Mann
Test Match Special commentator

Stokes has been positive right from the start, his body language has shown he wants to put England in charge. It's been a good knock and it's only his second ODI half-century in this country.

Image source, Getty Images

50 for Stokespublished at 28 overs

28 overs

Target 248

Oooh, good news Pakistan fans. Irfan's back near the boundary edge doing some stretches. Cue a couple of jokes on TMS about how long it will take him. Meanwhile, Stokes gets to his half-century with a double off Nawaz. No big celebration of course. Casual raise of the bat, the Headingley PA system blares out some popular ditty of the age to drown out the crowd. Usual stuff, really.

Graeme Swann
Ex-England spinner on BBC Test Match Special

That was beaten for four by Jonny Bairstow.

Bairstow always seems like he's run a 100m dash before every ball, that mouth open, panting, that high back lift poised to attack. And attack it does as Bairstow leans in to a good length delivery from Hasan Ali and smoothly drives it through cover for four. Don't even bother running after that. The right-hander then tries a hefty pull but can't connect properly and the ball clips off his own body. 

Bairstow must have felt a bit bogged down in that last over from Mohammad Nawaz, but steals a single off the final ball to retain strike. Hasty effort but he got to the non-striker's safely in the end. The sight of four shadows radiating from each player under floodlights one of the best in cricket, everyone's in agreement yes?

Image source, Getty Images

Graeme Swann
Ex-England spinner on BBC Test Match Special

Irfan has been the x-factor for Pakistan tonight.

Cheers Marc. The sky over Headingley has gone very Lord-of-the-Rings dramatic on us. England have avoided a fair amount of drama since the four wickets fell. Plenty of time to kick things up a notch. Also, shout out to the masseur who probably gets double pay for treating Mohammad Irfan. Welcome to the meaty part of the run chase!

Pakistan skipper Azhar Ali turns to Mohammad Irfan for a bowl, but the big man is sore and has to troop off for some treatment.

Instead, Hasan Ali is into the attack. With Ben Stokes a four away from his half-century, he does well to keep the burly all-rounder in check.

And on that note, allow me to introduce Bibhash Dash. Enjoy the rest of the game.

There's a steely determination about Ben Stokes, who brushes off that close call for both himself and Jonny Bairstow by hammering the ball through the leg side for four more.

He ends the over with a delicious cover drive for four.

England taking control.