Dustin Johnson misses out on a birdie but it's still an important par on the 14th given Brooks Koepka's current situation.

Earlier, Lucas Bjerregaard got a hole in one on the 17th before his playing partner Lucas Glover chipped in from the bunker. It was a lot of fun.

"We were discussing the wind quite a bit before," said Bjerregaard on Sky Sports. "We couldn't quite see it go in but the reaction was amazing. The New York fans were really loud."

"It was obviously pretty special," added Glover. "We had an awesome celebration. I haven't been that jacked up on a golf course for a long time. I'm not sure how we hit our tee shots on the 18th, we were so amped up."

Andrew Cotter
BBC Sport commentator

He's suddenly looking mortal.

Foooooorrrrrrrrrrrrrrreeee. Brooks Koepka takes the big dog out but he'll need a sat nav to get back from there.

Looks like he's in big trouble down the left. Four shots doesn't feel that secure right now.

Image source, Getty Images

The only par five on the back nine gained a new tee in 2009 and also extra deep bunkers left of the drive zone. Two good shots will set up a birdie chance, but one miscue could create real problems.

How's Brooks Koepka's nerve?

Don't know if he heard, but Dustin Johnson seems to sense he has a chance to attack on the 14th after Brooks Koepka's dropped shot.

It's a decent tee shot on the par three, could Johnson reduce the lead to three shots?

Bogey. Bogey. This is not over. Brooks Koepka doesn't quite read the green on 12 and drops another.

Did Dustin Johnson hear that gasp from the gallery? Four shots is nothing right?

Safety first from Brooks Koepka as he lands on the dancefloor in three.

A par putt from 16-feet coming up.

It's Mary Poppins weather out there at the moment. I thought the wind only blew like this on a links course!

Even Brooks Koepka is having one or two issues, going way off course on the tee into the rough on the right.

He should have brought a kite out with him.

A great putt from Dustin Johnson up the hill on the 13th green. He saves a par after a wayward approach shot. On -2 for the day, the American is the only player in the top 10 under par today.

Could Brooks Koepka get close?

Rough day for Danny Willett.

Five bogeys and two double bogeys in all for the Englishman. We've all been there, Danny.

We mentioned that Jazz Janewattananond had found himself in the long grass and, as expected, it's not ended well.

That stuff is so hard to get out of and his first attempt only went about 20ft.

He ends up with a double bogey on the 12th and is now on -3.

Dustin Johnson is -4 on average on holes 12-18 this week. Not sure that's going to help him with the way Brooks Koepka is playing though.

The wind is not his friend, it's caught his third shot and brought it down in front of the green on the par-five 13th.

Stating the obvious maybe but a good bit of context from American golf journalist Jason Sobel.

Image source, Getty Images

You have to play safely to the right of the deep cross-bunker and leave yourself a long approach or try for a 260-yard carry. The prevailing wind is against and the green has a pronounced tier.

How is this going to play in the swirl today.

Two mistakes on the spin?

That's a touch heavy-handed from Brooks Koepka as he races past the cup by six or even feet. He atones for that nicely though limiting the damage to a bogey.

Blanking out a mistake is one of the hardest things to do in golf. This fella virtually presses erase each time and it's gone. The lead is at five strokes.

Lucky break for Matt Wallace on the par-five 13th. His second shot skids through the rough and is spat out onto the fairway.

No luck involved in his approach though, it's a superb chip on and rolls just left of the hole. Should be a par though.

The wind is really starting to get to Dustin Johnson now. His tee shot has gone right on the 13th and he's in the rough.

Jazz Janewattananond could soon be dropping a shot on the par-four 12th. He's gone in the long grass. We saw Harold Varner III come undone in it earlier, it's evil stuff.