Rickie Fowler with a splash of dust into the sand on the 16th near this green. Brian Harman pin seeking on the 14th and doing it nicely. That bring sup a birdie chance... still in it...

Koepka is now flirting with equalling or even bettering Rory McIlroy's US Open record-low winning score of 16 under.

The American has been calmness personified today and yet again nails his approach to set up yet another birdie chance on 15.

No such togetherness for Fleetwood. That's a bad error, sliding off the green and away, far away.

US unless stated.

-14 B Koepka

-12 H Matsuyama (Jpn)

-11 T Fleetwood (Eng), B Harman

-10 X Schauffele

-9 B Snedeker, B Haas, R Fowler, C Hoffman

-8 T Mullinax, J Thomas

-7 JB Holmes, S W Kim (Kor)

-6 B Steele,P Reed

Selected others: -5, S Stricker, JB Holmes, B Wiesberger (Aut), -4, D Lingmerth (Swe), S Garcia (Spa), -3, E Pepperell (Eng), L Oosthuizen (SA), -2, P Casey (Eng), -1, Z Johnson, J Lovemark, M Lieshman (Aus), E, M Laird (Sco) +1, J Speith, M Kaymer (Ger), M Fitzpatrick (Eng), +2, A Johnston (Eng), +3, S Lowry (Ire) +7, E Els (SA), L Westwood (Eng)

View the full leaderboard here.

I gave Patrick Reed the big sell before the start of his round earlier after his 65 yesterday.

He's done nothing all day except just now, with an excellent putt for birdie on 16.

Two bogeys otherwise, the American is seven under.

Image source, Getty Images

You have to feel Rickie Fowler's charge has fallen away as he misses a par putt on the 15th. Both he and Kim Si-woo have infected one another. Kim makes bogey again and is three over today, no birdies to show.

Image source, Reuters

Xander Schauffele plays the final hole of his first major with the kind of distinction he has shown all week. The par five is no challenge for him as he rolls home a four-foot birdie putt.

This young man is just 23, so what kind of a future awaits? Ten under in a US Open and currently in the top 10. His bank account will get a nice boost.

No dramas off the tee for these two at 15, both finding the fairway.

Iain Carter
BBC golf correspondent at Erin Hills

That was a must make from Tommy Fleetwood.

And Fleetwood matches his partner from three feet to remain three shots behind Koepka.

Four holes for someone to make a surge. Four holes for Koepka to stay calm.

A tricky three or four foot putt for Koepka.

He'll want to go right at it, but will nerves get the better of him? No chance.

The imperious-looking American takes a two-shot lead.

Image source, Reuters

Oh hello, Tommy Fleetwood is not done here. The Englishman gets a great roll on his third shot at 14 and it spirals closer and closer to the hole.

Here comes Koepka, deep in the bunker. Genius. What a chip that is, lands it perfectly with a bit of spin back to give himself a chance of birdie.

Image source, Getty Images

Brian Harman showing what the back nine of a US Open can do to you. His knees tremble over a short par putt on 13 and there are no prizes or positive headlines for that kind of miss.

Oh what a superb shot from Matsuyama at 17 - he miscued his second out right but drops his third to just three feet away.

Can he convert? Oh you betcha. Matsuyama gets to 12 under.

That's a huge clubhouse lead to post. Could it even be a winning score?

Whatever happens, a round of 66 in this wind is exquisite.

Rickie Fowler on a par five, he must, simply must nail this drag. He lays up and makes an error in allowing his ball to trickle into the thin rough. His third shot then, put it close Rickie... he can't. It's short of the green. A bump and run it is then and it's almost holed. Cracking effort but this par will not win any majors.

Brian Harman trying to forget his bogey on 11 and if he drains the 33 footer he has left for birdie on 12 he'd be happy...leaves it out there though.

Image source, Getty Images

Koepka buries his second shot at 14 into a bunker. That went straight in and could've plugged.

Jay Townsend
BBC Radio 5 live at Erin Hills

Leonard Odicean asks: Why are so few Europeans on the leader board?

There's no reason for Europeans not to be playing well, we are actually on a course that I would have thought would suit them well.

You ask the questions, the guys will try and answer them. Tweet Iain, Jay and Chris at Erin Hills on #bbcgolf

Brooks Koepka, casting a shadow with his broad shoulders here, leads the entire field this week in finding greens in regulation. The American has found 57 of 67 which on a course like this, is mighty impressive.

Image source, Getty Images

Matsuyama goes eagle hunting at the last, trying to belt it with a three wood onto the green in two.

Ack, he steps back, doesn't like it and off it spirals right and into the rough.

If he can scramble an up and down in two he could still grab a birdie. Outside chance now though.

That saved shot from big burly Brooks looks even bigger now as Brian Harman pays for his hooked drive on the 12th. Harman hacked out of the monster grass and then played up to the green, leaving the approach short. No way was he ever making the par putt from off the dancefloor so one gone.

Image source, EPA

Big, big putt from Koepka as he strokes in his par effort from about nine foot. That'll feel as good as a birdie after his poor chip.

Fleetwood has 12ft for his par - and he nails it too.

The Englishman isn't out of this yet but he'll need Koepka to start faltering. The only problems is that these two seem to keep bringing the best out of each other.

Little he can do about Harman behind him though.