Another chance slips by for Rory McIlroy. He starts his ball straight at the hole but it drifts off left at the last.

Michael Block needs two putts from 25 feet for a bogey.

My colleague has just messaged me with the following...

'Don't be fooled by the shots that he's dropped, he's still, he's still Michael from the Block.'

If you like that, thumbs up. If you think my colleague should be fired on the spot, thumbs down...

Hovland digs out his chip shot nicely, again showing short game skills, and then he finishes it off with the birdie putt from around eight feet.

It briefly gives him a share of the lead before Koepka follows him in with a tap-in to restore his one-shot advantage.

You will struggle to see a straighter tee shot than the one Scottie Scheffler has just lamped 300-odd yards down the 16th fairway.

With Viktor Hovland and Brooks Koepka one and two shots ahead respectively, Scheffler is surely going to need a birdie or two from these final three holes.

He'll be regretting the ordinary round of 73 he posted on Saturday when he slipped in the wrong direction on moving day.

Michael Block is a quick player. No fuss, walk up to the ball, address it and hit it. It's not working for him on the 16th.

He's in the cabbage off the left side of the green and has work to do. His chip on is a bit strong and he's going to have a 25-footer for par.

Rory McIlroy has gone pin hunting with his second, firing one in to about eight feet.

Justin Rose has nailed some monster putts this week and here's another to add to the collection as he converts one almost the length of the 15th green to get back on the birdie train.

Too late to challenge now - unlike playing partner Scottie Scheffler who remains in contention with a par after chipping on from the fringe.

Hovland comes up just short and in the rough in front of the 14th green, which is the short par four that's driveable for these guys - especially Koepka.

And Brooks dosn't disappoint as he gives the big dog a rip and it ends up about pin high and just on the fringe of the green. Shouldn't be too many problems get down in two from there for a birdie.

Nice to see a bit of trending upwards for this pair on the short par-four 14th.

Corey Conners' putting radar has been off all day but he finds his range here and tucks in from 20 feet.

Bryson follows him in for a birdie.

Michael Block is on a differet planet to the tour pros that he's played with this week.

He holds his scorecard up in front of the TV camera as he marks his card with a 1 - before circling it for added emphasis - and chuckles as he does so.

The 46-year-old is playing in his fifth PGA Championship but had never made the cut before this week. Now he's joint 13th and if he stays in the top 15, that's an automatic invite back for next year's tournament.

What Scottie Scheffler would have given for a Block-esque tee shot at the par-three 15th.

His effort fails to threaten the flag, however, and he's a bit lucky it clings to the right-hand fringe of the green, rather than rolling off.

Image source, Getty

Hovland with a nerveless 10-foot putt on the 13th to pick up a birdie and heap some pressure on Koepka who has a testing par saver from six feet.

Koepka is equal to it though and he stays in front on his own, with both men showing they've got the nerve to see this through.

While Block is surveying the scene, his playing partner, the world number three, is struggling to make par.

Rory McIlroy drifted right off the tee and down a steep bank. The chip up is average and he's got a 16-footer to save par.

That's a bit speedy and Rory will have a three-footer for bogey. Shot gone.

Image source, Getty Images

Amid all that chaos in front of him, Scottie Scheffler is going about his business.

Escapes the sand on 14 to give himself a birdie putt - and tucks it away from 10 feet.

That's five birdies in eight holes - marred slightly by one bogey in there too - and he's just two shots off fellow American Brooks Koepka.

Bryson DeChambeau is submerged in the thick rough high to the right of the 13th green.

He chunks out a recovery shot but it arrows past the hole and any hope of a birdie disappears.

He needs to do a Block on the next two holes to have any chance.

Iain Carter
BBC golf correspondent at Oak Hill

A moment of raw emotion for Michael Block and it just reminds you at a time when this game of golf is beset by all sorts of schisms and so much money at play, that this maddening game still has moments of pure romance, and that is one of them

Image source, Getty Images

There's a high-five and a hug from Rory McIlroy, who is laughing his head off.

"Did it go in? Did it really?" asks a completely bewildered Michael Block is cheered the entire length of the 150-yard hole.

What a brilliant week this Californian club pro is having. Just sensational. And that gets him back to level par for the tournament too.

He said at halfway that he'd finish at level par. Three holes left to focus on... and then it's one expensive round of drinks coming up!

If Oak Hill had a roof, it would have come off!

Oh. My. Word.

Michael Block with a slam dunk hole-in-one on the 15th.

Scottie Scheffler has birdied the 14th every round this week and he goes aggressive off the tee here, maybe too aggressive.

He finds a bunker down the left but the 14th is such a short par four that it's far from disastrous.

Justin Rose's race, meanwhile, looks run after three bogeys in five holes either side of the turn - he's playing for place money now.

"Great shot," says Rory McIlroy to playing partner and club pro Michael Block after he flicks a wedge in to eight feet on the par-four 14th.

Nice praise. Block looks like God has just spoken to him.

Rory is playing out of the thickest of the rough but gets his ball fractionally closer and, crucially, on the same line as Block's.

He gets a great read as Block's birdie try drifts right.

Rory, to keep pushing... NO! Awful miss that really, given he knew what would happen to his ball.

The 2019 Open Champion, Shane Lowry hasn't really been in the conversation over the weekend but could he be finishing with a flourish.

After an eagle two at the 14th, he comes up with a birdie at the 16th hole after a stunning iron shot into five feet.

Much more like it.

Brooks Koepka with a mightily impressive birdie at the 12th to strike right back after the bogey on the previous hole.

He's been firing at flags all day with his irons and although this one just catches the fringe, it's only 10 feet and Koepka dunks it in.

Hovland can't answer with his own birdie try so the lead is back to two again.