Brilliant from Keegan Bradley on the third hole as he stripes another pure iron shot from 211 yards on the par three up to just nine feet - and makes sure he doesn't waste a strike like that by making the putt to join Conners in the lead.

The tell-tale signs of a missed birdie. Knees buckle, stance rocks back and hands up to your head. Rory McIlroy can't believe his left-to-right effort hasn't dropped on the sixth although it could be worse.

JT duffs a couple of putts from six feet or so to end up with a double and Collin Morikawa escapes with a bogey after finding water, well a stream, off the tee.

Viktor Hovland's recovery mission fails with that 15-20 footer well right and never showing signs of coming back left.

Tidies up but that's a bogey and the Norwegian drops out of a share of the lead.

It was all going swimmingly for Kazuki Higa after 14 holes before his round collapsed in his last four holes.

Higa doubled the sixth (his 15th) then came home with three more straight bogeys to plummet from three under to two over as he's given a harsh lesson in how you have to finish your rounds in major championships.

Scottie Scheffler is turning it on as he closes his round.

A delightful iron from the middle of the eighth fairway drops bang on the pin and he will have a short putt to claim a birdie and a share of the lead.

Image source, Getty Images

Fancy a quick look at the scores on the doors early into this first round, well I say early but nearly six hours in.

-4 Conners

-3 Fox, Hovland

-2 Theegala, Scheffler, Bradley DeChambeau

-1 Thomas, Morikawa, Tarren, Suh, Hubbard

Image source, Getty Images

Bryson DeChambeau has appeared all of a sudden after a run of birdies and is lurking just off the leaders with menace.

The huge-hitting DeChambeau has abandoned his bulking up phase and slimmed down but still hits it miles.

He's not been in great form in his new LIV Golf career but successive birdies have put him in touching distance at Oak Hill - which has been likened to Winged Foot where he won the US Open a couple of years ago.

Hang on, maybe the bogey was not so inevitable.

A wonderful recovery shot from Viktor Hovland takes a nice little hop, skip and a jump on to the sixth green from the drop area and gives him a squeak of a chance to rescue par.

Still a good 20-footer though.

After a frosty start that delayed the start by almost two hours, the jumpers and hoodies have been discarded and it's short sleeves weather for most of the players now.

Jon Rahm has ditched his powder blue top and is looking like he means business on the fifth tee. Par three. Birdie hole?

A slight tug leaves him scrambling from the rough to make par. Just six out of 14 greens hit by the Spaniard. A decent chip to three feet.

Matt Fitzpatrick may be forced to eat his words about enjoying tough golf courses - he's in the sand off the tee can only hack out and leave a 60-footer for par.

Oh, Viktor!

Fades a drive on the par-four sixth hole directly into the water running alongside the fairway on its right.

Almost certainly a bogey incoming.

A 20-footer doesn't drop for Scheffler but he'll pack another tidy par into his golf bag with two holes to go.

He's played serenely so far today.

Image source, Getty Images

Remarkable. Rory McIlroy looks in all sorts of bother way out left in the gnarly stuff and then sends a tracer into 12 feet on the sixth. From out of literally nowhere he'll have a birdie putt.

You just can’t take your eyes off him.

By the looks of it Collin Morikawa is in big trouble, last I saw his ball was drifting off right towards Allen's Creek.

Jon Rahm almost sinks to his knees in frustration on the par-five fourth. He was out of position off the tee but got himself back onto the fairway and hit a pin-seeker of a third into about four feet.

But the birdie putt sidles by on the right. He can't quite believe that's missed.

Cam Smith shows the benefit of staying in the fairway off the tee, sending his second hunting the green. Two shots from 70 feet and that's a welcome birdie.

Matt Fitzpatrick has zig-zagged his way down the hole but walks off with a par.

Scottie Scheffler has been typically excellent from tee to green today and he's found the putting surface in two once again on the par-four seventh.

He'll have a birdie shot for -3 and one behind leader Corey Conners.

It's still a grind for Brooks Koepka. He's in the bunker to the right of the green.

It's back-to-back birdies for Corey Conners as he gets to four under and lead at Oak Hill on his own.

Conners eats up the short par-four 14th by sticking his approach to six feet, and doubles up on 15 with a decent iron shot to the par three followed by a magnificent putt from 30 feet to stick his nose in front.

Up goes the shout of 'fore' on the 6th tee as Rory McIlroy's tee shot sails well, well left, maybe even taking the fairway sand traps out of play.

It appeared as though the spring was back in his step just a couple of holes back.

Europe's Ryder Cup captain Luke Donald received an invite from the PGA for this tournament and the 45-year-old Englishman is making the most of it.

A solid level-par round so far almost went into the black with a long-range birdie putt on the third green, must have been 30-35 feet, but it just drifted millimetres wide left.

But a score of even is very respectable on this difficult course, especially when you see some of the big names who are struggling.

Scottie Scheffler takes a par. Gary Woodland takes a par.

Can Brooks Koepka join them?

Yes, he slides in for a four.

Sixth hole safely navigated.

Now into new territory here so to speak for Rory McIlroy on the fifth which is a newly constructed hole from his last trip around this track a decade ago.

JT was in his first year as a pro back then, while Collin Morikawa was only 16.

All three fail to land in makeable birdie range with defending champion Thomas scrambling to make par from the front bunker and Morikawa take two putts from 40 feet to secure his three.

Rory McIlroy frustratingly can't save his. A first putt halts five feet shy of the hole and his second slips past on the high side. The the ups and downs of golf, folks in just 10 shots!

Matt Fitzpatrick is usually so reliable with the putter, particularly from inside five feet. But he misses one on the par-three third, after clipping a bunker shot to four feet. Shot gone.

And it's a copycat bogey for Jon Rahm, missing a five-footer after knocking out of the same bunker.

A two-putt par for Cam Smith. But this group of major champions are all the wrong side of level par and for Rahm and Fitzy, it's worrying times.