Koepka to test his short game on 6 - he's left himself a tough par chance, can he make it? Yep, that's a decent save.

Fleetwood has a chance at birdie but underhits it slightly. Par for him too.

(All US unless stated)

-8 Tommy Fleetwood (Eng), C Hoffman, P Reed, B Koepka, B Harman

-7 R Fowler, J Thomas, M Leishman (Aus), B Steele, H Matsuyama (Jpn), X Shauffele

-6 J Lovemark, B Haas

-5 S Scheffler (a), R Henley, JB Holmes, P Casey (Eng), B Snedeker, S W Kim (Kor),

-4 L Oosthuizen (SA), E Pepperell, P Casey (Eng)

Selected others:-2, S Garcia (Spa), -1, A Johnston (Eng), +1, Matt Fitzpatrick (Eng), E, M Laird (Sco), A Hadwin (Can), +2, E Els, +3, L Westwood, +4, E Els (SA)

(a) Amateur

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Paul Casey is really suffering right now. He follows his triple bogey on three with another drop on four. The tee shot was again up the fairway but it got away from him from there in.

Playing partner Brian Harman rejoins the leaders with a birdie. Two good shots into the dancefloor and that's the reward you get. He stroked home a beauty with right-to-left break.

We have five leaders... though Justin Thomas may well be about to change things...

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"Be as good as you look," pleads Justin Thomas after his tee shot on 15. Oh it's even better, it's absolutely gorgeous. A cracking strike that hits the back edge the green and spins back.

He's got a fantastic chance of an eagle and the outright lead.

Fleetwood misses out on a birdie but he's looking very assured out there.

His partner Koepka looks to have settle after his brief wobble and strokes in a birdie at the 5th to make it a four-way tie for the lead.

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We've barely given them a mention so far but the pairing of Marc Leishman and Brendan Steele are playing very nicely indeed.

They've both moved to seven under at the turn, three under for their rounds, but have taken very different routes.

Leishman has three birdies and six pars. Steele has five birdies, two bogeys and two pars.

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Matsuyama rolls in his easy birdie chance on eight and moves to one shot off the lead.

We are asking if you are a golfing lookalike and Robbie Thomson has come up trumps.

Robbie, we love you. Keep them coming to #bbcgolf.

So Tommy Fleetwood is the co-leader once again - here's his second on the 5th.

Stellar stuff, clipping a deft stroke towards the pin and giving himself a grand chance of birdie.

Image source, EPA

Suddenly the crazy scoring has halted. Brian Harman caught whatever playing partner Paul Casey was carrying on the third and made bogey too.

But the man of the moment Charley Hoffman has picked up the bug too. An underhit chip on the 10th leaves him a long way away when lining up a par putt. He can't pull this one out of the bag and he loses the outright lead.

Hideki Matsuyama is a loooong way back on the 8th but drills a monster shot right at the pin. Is the Japanese star ready to make a charge?

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They both had their struggles on the fourth but Tommy Fleetwood and Brooks Koepka both execute impressive up and downs to make par.

Patrick Reed has yet another birdie chance at the last!

Here it goes......oh just missed. It's still a cracking round of 65, equalling the best round of the weekend alongside Rickie Fowler on day one.

The American is the clubhouse leader and has put himself right in the mix for tomorrow.

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Image source, EPA

Paul Casey is in big, big trouble on the third hole. It started well when he found the fairway but pushing a ball right into the thick rough can mean the end of you at Erin Hills.

He studies his ball for a while and swings hard as he tries to flick it onto the green. Zero sight of that ball coming out of the thick grass though. Try again... this is shot four... clunk. The ball fizzes out and off the green.

Still, he has work to do... this putt from off the surface needs to go close. It comes to rest 10ft away. Now putting for a double...it slides right. Triple.

That was the stuff of nightmares.

Si Woo Kim and JB Holmes were the fourth last pairing out but have already fallen back to tied 15th, both making bogeys, although Kim has a birdie to ensure he's level for the round.

As golf reporter Robert points out, Reed could level a glut of men who have hit a 63. Charley Hoffman will need another five birdies to make the 62 golf has never seen.

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...and it's Brooks Koepka whose woes continue on four as he hacks out of the deep rough but nails his attempted rescue shot into the bunker.

Is it catching? Tommy Fleetwood then also finds sand, despite taking his shot from the fairway. Looks like too much spin on it to roll back into the bunker.

Fleetwood's first error - can he recover?

Brian Harman has some kind of fairway wood in his hand on this third hole and with over 200 yards to go he's swinging hard... too hard. Over the green and problems.

Paul Casey is in the fairway, he'd take par on this drag. Iron for Casey and he's in some deep trouble out right. Suddenly a few wobbles and there's one on the fourth too....

Image source, Getty Images

Is Charley Hoffman about to make his sixth birdie on the front nine? It looks good, but the ball just slides past.

Still, a remarkable first nine holes from the Hoff to lead on nine under at the turn.