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Huge roars from the crowd as Scottie Scheffler's wedge to the par-five 13th spins back dramatically and threatens the hole - but just drifts by.

No eagle but it's a golden birdie chance and the world number two obliges. He's just two off the lead after a brilliant run of birdies.

Oh, hang on, it's not two behind, it's three...

Iain Carter
BBC golf correspondent at Oak Hill

One of the things that Brooks Koepka has learned since The Masters is just to slow down.

You can get out of your rhythm and you can start going quickly when you're nervous.

I think his demeanour is slightly different a month on.

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Painful bogeys on 12 for Corey Conners and Bryson DeChambeau - and you have to feel their challenge is done now.

Errant off the tee, they're both scrambling to save par but no luck.

There's a distinct air of disappointment about DeChambeau as he trudges off towards the 13th tee.

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Kurt Kitayama is enjoying an excellent 2023, having registered his first PGA Tour victory at the Arnold Palmer Invitational earlier in the year - despite a triple bogey in the final round.

The 30-year-old American, the world number 21, pars the 18th to sign for a fabulous final-day 65 to tie Australian Cam Davis for the clubhouse lead on three under par for the tournament.

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Koepka played that bunker shot about as well as you could expect, but he's left himself 15 feet and his putt just doesn't break enough off the left.

So that's a bogey, eventually, after he takes quite a while to tap in from a foot, Patrick Cantlay would be getting all kids of criticism for that...

There's a big cheer over by the 13th green after Rory McIlroy's well-judged wedge leaves him a four-footer for birdie.

The cheer goes up a few decibels when the two-time PGA champ knocks in the putt.

That's three birdies in five holes and the Northern Irishman is closing in on another backdoor top-five finish at a major.

Michael Block takes two to make par.

Zane Scotland
Former European Tour player on BBC Radio 5 Live

That was a real bit of magic from Koepka. He has a lot of power and he had to get up so quickly - it's like a wall in front of him in that bunker and that could be a defining moment for Brooks Koepka there.

Urgh - Koepka's got a real test coming up now as his tee shot at the long par three thumps into top of the bunker and although not totally plugged, is the classic 'fried egg' lie with sand surrounding it.

It's also pretty steep in there so Brooks will have to become a mountain goat to get up to the ball.

There's a pretty high difficulty tariff on this shot.

"Be right baby," says Michael Block after flicking a wedge into the green with his third shot on the long 13th.

It's a fair to middling effort, the ball coming to rest 25 feet from the hole.

Rory McIlroy is 55 yards short of the hole after two mighty blows on the 612-yard hole.

Four shots adrift of the lead, world number two Scottie Scheffler cannot afford ordinary shots like the iron he's lofted on to the safe side of the 12th green.

It leaves a mammoth birdie putt which, in fairness, comes close. But par, it is - and he's beginning to run out of holes, unless Brooks Koepka throws in a couple of shockers.

Iain Carter
BBC golf correspondent at Oak Hill

Jon Rahm was saying of Brooks Koepka that he's like a shark in the water when he can smell blood.

That certainly sprung to mind when that putt dropped for Koepka. A really big blow to strike at the start of the back nine.

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Hovland's birdie effort from 20 feet looks in all the way until a late swing sees it lip out, but coming down the hill it wanders off another five feet.

Koepka then strokes in his birdie putt from six feet to pile all the pressure on the Norwegian, but he answers superbly with a par save to keep the lead at two.

Austria's Sepp Straka is home and hosed with a superb five-under 65 for his final round to leave him at two under overall.

His trip down 18 ends in slightly disappointing fashion mind with a bogey after finding the right fairway bunker off the tee and proceeding to spin into the rough twice.

Still as it stands he's in the clubhouse and in a tie for eighth, which is comfortably better than his best finish in any other major to date which was T28 at the 2019 US Open.

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Rory McIlroy has just been a fraction off target all week. He's in the fairway again on the par-four 12th, with a wedge in hand but fires slightly long and although his ball comes to rest on the green, he's still 30 feet from the hole.

The birdie putt slides by on the left. Par is good but it perhaps could have been so much better.

Michal Block ticks off another par. He's currently joint 17th and eyeing up a payday of around $250,000.

There are good scores out there given the friendly conditions today and that's being proven by some of the names climbing towards the top of the leaderboard, seemingly out of nowhere.

Australia's Cam Davis and American Kurt Kitayama have both rocketed into a tie for fourth on -3 after rounds of five under for the day - and they both still have a hole or two to play to improve further.

The pace of play tonight is quite something, and no sooner had Scottie Scheffler landed that birdie on 10, he had an opening for another on the par-three 11th.

No dice this time, though, as he rolls a mid-range effort just to the left of the hole.

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That bogey is going to smart for Bryson DeChambeau after a serious misjudgement with his approach to the 10th green.

He sizes up a nerve-shredding seven-footer for par but it teases the edge of the hole and rolls on.

Iain Carter
BBC golf correspondent at Oak Hill

If Koepka gets the job done, we saw high finishes for LIV players at The Masters as well. It just reminds everybody that this breakaway league that is funded by Saudi Arabia can claim to have some of the biggest names, the biggest personalities and some of the best golfers there.

You can bet your bottom dollar that they will be looking to exploit that every which way that they can as this golf season progresses.

Right then, where do we stand? I'd have had the engraver out carving Brooks Koepka's name on the trophy after four holes after his hat-trick of birdies led to an even more pronounced strut down the fairways.

He's just shown a few signs of nerves, but after his wobble he looks to be on an even keel, and he's gobbled up the back nine this week, so he's still big favourite.

Viktor Hovland has been quietly going about his business with just one bogey spoiling his round do far. And his short game has been top notch - it's anyone's game!

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Viktor Hovland's playing like a Norwegian, right-handed Phil Mickelson around the last couple of greens, as he makes a treacherous chip shot look pretty easy.

He has to stab it out of the rough, send it high and land it softly enough that it won't take off down the slope, and it's near perfect in execution as it trundles down to about three feet.

Hovland knocks in for par after an A+ up and down.