Two groups left in the lengthening Augusta shadows... Justin Thomas groans as his ball hits the dancefloor and slides back down the slope after almost pirouetting with Justin Rose's ball.

That would have led to an interesting convo between the two men if Rose's out suddenly became so much more difficult.

Bryson DeChambeau taps his birdie putt in after that incredible second shot on 18 and ends with a 66 to join the lead.

Dustin Johnson has a nasty up and down... gets it done. That's four under for his 18.

Jason Day now - still going with injury - converts a five footer for par and a round of two under.

Day will need physio, Johnson will undoubtedly be chilled, DeChambeau needs extinguishing as he's on fire.

The wheels are coming off for Koepka! We joke. But he is in, for him, a spot of bother. He dunks his approach to the 17th into the bunker guarding the green.

But a splash-tastic third leaves him with another tap-in for a sandy save.

Quite incredible from Bryson DeChambeau.

He uses a fairway metal off the tee on 18 and settles in the first cut to the left of the fairway. What follows is a quotes stunning iron into the green. It skips and jumps and arrows at the cup, hitting the flag stick and resting an inch away.

He is going to finish with four birdies in a row.

We've all been there Matt.

Phil Mickelson buries a par putt on the 17th after his foresty work, while Justin Rose is currently on the see-saw.

The world number one goes birdie-bogey-birdie as he balls clings onto the right lip and is eventually sucked down the trapdoor.

Did we tell you Phil Mickelson tucked away that birdie putt on the 16th? Well, it was obvious.

Now Leftie has gone off piste on the 17th. But if there is a better player out of the trees than him then they had better step forward and show themselves. He uses those irons like a chainsaw.

He cuts out of the pines and sees his ball hit the green...

Justin Rose, meanwhile, dropped a shot on the 16th. So much for that birdie kick-starting his Masters...

Francesco Molinari gives us all a slap and reminds us there's an Open champion in the field.

He'll sleep well tonight after sending home a long, snaking birdie putt on 18. That's a 70 - and two under.

In the mix.

Alistair Bruce-Ball
BBC Radio 5 live commentator at Augusta National

If Brooks Koepka were to go on and win here then you would be going to every single major championship looking for a player to complete the career Grand Slam.

Rory McIlroy at the Masters, Phil Mickelson at the US Open, Koepka at the Open and Jordan Spieth at the US PGA, which would be very exciting for the game.

Brooks Koepka sees the funny side of not hitting his birdie putt. Suppose you can when you're leading the Masters. The American gets his line spot on, but gets his weight wrong. No pun intended.

Jordan Spieth, his playing pal, finally gets some respite with a birdie two.

Iain Carter
BBC Sport golf correspondent at Augusta National

Kiradech Aphibarnrat has really shown again what a world-class player he is.

He has taken the applause on the 18th hole after getting up and down and coming home in 32.

Oh Brooks, stop it! Moments after Bryson DeChambeau cuts his lead back to one, Koepka nails his tee shot on the 16th. Over the water and about 10 feet from another birdie...

My oh my.

Bryson DeChambeau showing he has some guts to go with a scientific brain.

He's in the trees on 17, does what he can to find the back of the green and looks to be scrapping for a par. Out comes the wedge, a clip, bounce and run... straight in.

That's how you turn a wayward drive into birdie.

Andrew Magee
PGA Tour winner on BBC Radio 5 live

How impressive was that from Brooks Koepka. He got a break off the tee and then played a great chip.

But you have to have a bit of luck with some great play. He missed last years Masters due to a wrist injury and he's probably felt like he needed to validate that absence.

Never. In. Doubt.

Brooks Koepka is flying. It could have been a no-look putt from the leader. That's his fourth straight birdie - his fifth in six - and moves him two ahead...

Anyone need some great shots?

Thought so.

Drink them in. Vote for the best by clicking here.

John Murray
BBC Radio 5 Live

Paul Casey looks disconsolate at the moment. He has his left hand in his pocket and has his head down as he turns to have a quick word with his caddie.