Katherine Downes
Radio 5 Sports Extra commentator

Listen to the roar of the crowd. There were boos and jeers on the first tee and now they're on their feet for the two-time PGA champion.

Three under par today - the best of any player, Koepka has got it moving and he is now within a shot of the lead.

Once again he is contending at a major championship after that runner-up finish at The Masters last month.

Just a small sign of Conners feeling it a it as he leaves a long birdie putt well short and gives himself a bit more stress than he'd like on the par save.

Let's not doubt Conners from four feet though - as he sinks that with the air of a man who's not missed much today.

Scheffler matches his par but really needs to start picking up some shots coming in.

Rory McIlroy has a horrid pitch here up the slope and to be honest this is pure damage limitation stuff.

He trundles past the pin by about six feet and his return putt just about grabs the left of the cup and disappears.

Shane Lowry has carded 13 pars in a relatively uneventful round and adds another here, rolling in from a similar distance.

Image source, Getty Images

He looks utterly unfazed by it but Brooks Koepka is very much in this.

Another birdie for the two-time PGA champion after watching Bryson DeChambeau's attempt to save par run of steam on the 13th green.

While his playing partner slips back, Koepka applies a bit more squeeze on the leading duo.

That collar of rough round the edge of the 15th green is indeed problematic for Justin Rose. He tries nudging it with his 3-wood but only advances it about two-thirds of the way to the hole. A six-footer for par.

Here's Michael Block. Eight feet. Birdie. He stops and looks around him, waiting for the reception - it's a mighty roar. He saunters off, shaking his head. Back-to-back birdies and back to level par for the PGA pro from California who charges $125 for a lesson.

Rose with a wry smile in the background as he lines up his par attempt. Solid.

Not for the first time this week Rory McIlroy is in trouble off the tee. And it was all starting to look so good.

He finds himself in the junk down the left and can only pitch forward and out into the left fairway bunker.

He's got zero control from there and airmails the green to the apron on the back left.

The cheers continue for Michael Block on the 15th tee. He arrows his tee shot in to about eight feet. He points to himself as he laps up the adulation. Brilliant scenes.

What can Justin Rose do? Left edge of the green, hanging on. He could be troubled by the collar of the rough though.

The 13th hole is playing every inch of its 617-yard backbone today as Brooks Koepka screams another terrific drive straight down the fairway.

His second shot skews a touch right but no such worries with his third as he plonks it on the green. An unlikely birdie chance.

Meanwhile, after finding the first cut with his drive, Bryson DeChambeau bounces his next two efforts into the rough as well to leave himself a skittish chip shot into the green.

His ball is where Justin Rose's was a few minutes ago - can he avoid what happened to the Englishman?

We have co-leaders again, folks.

After that remarkable backspin with the iron, Viktor Hovland converts from five feet and draws level on six under with Corey Conners.

These two began the day level at the top of the leaderboard and here they are joined at the hip again.

Corey Conners just has a liquid swing with the driver today - you just can't overstate just how good he's been playing Oak Hill today, especially off the tee, although his putting's been pretty spot on too.

He's just laced another right down the middle of the 12th.

Iain Carter
BBC golf correspondent at Oak Hill

For all the superstars that are in it, there characters that come to the fore at majors. A little touch of the knuckles with Justin Rose a pat on the back as well.

This guy Block loves being the centre of attention.

While Michael Block has been chuntering to the tv people, Justin Rose has flicked his wedge up to around 20 feet. No birdie though.

Block steps up and drains the birdie try. He looks around in complete bewilderment at what's going on as the cheers erupt once more for him.

Rose taps in for par and then makes a beeline for Block, giving him a big fist-bump and a slap on the shoulder. These two are having a ball out there.

Viktor Hovland screws the white ball back across the 12th green better than Ronnie O'Sullivan on the snooker table.

Unbelievable backspin.

It's about 15 feet past the pin when it lands - and ends up five feet the other side when it's finished spinning back.

The waterproofs are off again and Rory McIlroy is dialed in.

He hits a superb drive down the middle of the 16th and then lobs on with his wedge to six or seven feet before dispatching his putt to the middle of the hole.

The two-time US PGA champion moves into the top five, four shots off the lead.

That's three birdies in five holes.

Image source, Getty Images

Here's some more of the chat from PGA pro Michael Block...

"I'm living a dream - I hope I'm living a dream for all the Rochester folks because the support I've got from the people here has been unbelievable, and honestly across the country, it's been an amazing experience.

"I'm on cloud nine and having a good time."

On the Oak Hill course:

"It's been brutal, the rough is something unlike I've ever seen, it's insanely hard. But the course has dried up beautifully, I was worried about it watching on TV earlier but the drainage is amazing and the greens are perfect."

Brooks going through the gears on 12.

I mentioned that lovely iron on his approach and he's dead-eye from 15 feet. Up to third on his own.

After such a wild tee shot, Bryson DeChambeau is deft on the green and gets his long putt close. He'll be satisfied with his par.

Michael Block is having a long chat with the host broadcaster as he saunters up to his ball on the 14th. He's in the middle of the fairway, having laid up, and clearly wants to get back focused on trying to make a birdie. But he's asked another question.

He does a good job of shutting it down, takes out the earpiece and gets back to business.

His wedge is flicked in to about eight feet. "Eight feet, cool, I like it," he says as he puts the earpiece in and finds out where his ball has landed.

Katherine Downes
Radio 5 Sports Extra commentator

Corey Conners' every tee shot, it doesn't even need to be a drive, is straight down the middle. He's thinking about positioning on the fairway and that has got to have been a big part of his game plan, whereas others are not adapting and they're finding themselves in some really difficult positions.

Scheffler has a decent attempt from 30 feet for birdie that just misses, while Conners leaves himself a couple of feet to tidy up - which as we know by now is not a problem for the Candian putting wizard today.

He's way out right on the 12th hole but that doesn't bother Bryson DeChambeau who has the benefit of a decent lie and a clear line of sight to the green.

One big swing later and his ball is safely landed on the dance floor - 32 feet from the pin.

Meanwhile, Brooks Koepka takes aim at the flag and it just catches the green, taking a lovely scoot off the front edge and flopping to 15 feet.

Birdie chance incoming.