What a superb round. Touches of genius, a minor wobble late on and then a stellar iron into the 18th green to bring up birdie.

Fred Couples, 57 years of age and playing like a 21-year-old. Two under for the day, one under overall.

Paul Casey is alongside him. He aims his birdie putt some 20+ft left of the hole and it swings back to end maybe three inches from the cup. What judgement.

Martin Kaymer rolls home a solid par putt on 16. He's playing like the major champion he is suddenly. Two big holes left for him - currently at two over.

Justin Rose is eagle hunting on 15... middle of the fairway he swipes at it and then shields his eyes from the sun... long... over the green. Up and down for birdie?

Image source, Reuters

Don't want to alarm you, Fowler fans. But... your man Rickie walked off the last with a double bogey yesterday.

Can't see that happening today on the evidence of his tee shot. 

Fowler hits a drive which has a fade more perfect that an footballer's expensive haircut. 

Cues cheers from the gallery, cue a confident walk up the middle.

The crowds around the 18th green are loving this. Fred Couples from the fairway uses the slope on the green stylishly... this could go in... close... wow.

Couples raises his arms, what a shot. He will surely make birdie.

More roars...noisy ones... it's the par-five 15th where Phil Mickelson holes out from just off the green for par. Big save. He puffs his cheeks out as if to say 'got away with that'.

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As things stand, a few big names will miss the weekend. Patrick Reed, Henrik Stenson and of course the champion Danny Willett. The cut line is at six over right now, so Willett needs it to move back one blow to survive.

The last time a champion missed the cut was 2004 - Mike Weir.

Jay Townsend
BBC Radio 5 live at Augusta

There are so many good stories, that is what is great about golf right now.

There are young guys, experienced guys, guys who should have won majors but have not done yet, guys who have won majors and want to add to their tally, old guys like Fred Couples who is out there and no one expects to win, but is keeping father time at bay. 

It is going to be an amazing weekend.

Rickie Fowler has hot-footed it up to the green. He can't wait to have a stab at this.

Up she goes from the fringe, Fowler chasing after it, swinging his putter in frustration.

Didn't hit it enough. A tap-in seals the par.

Like Pieters a few moments ago, he has one more chance to grab the outright lead at the halfway stage.

Back over to Rickie Fowler on 17. A beauty of a drive is sitting pretty, surrounded by yards of fairway.

Can he match that with a decent approach? The American's perfect finishing pose, chest out, arms high, mouth resisting the temptation to smile, tells you everything.

It's a beauty. About 15 foot past the flag, as good a chance of a birdie as he could have wished for.

-4 Charley Hoffman (finished his round), Sergio Garcia (F), Thomas Pieters (18), Rickie Fowler (16)

-2 William McGirt (F), Phil Mickelson (14),-1 Justin Rose (13)

Selected others: +1 Rory McIlroy (F), +2 Jordan Spieth (15)

Take a look at the  full leaderboard here, external , or find out more about the  BBC's coverage here.

Image source, Getty Images

What a save. Thomas Pieters knocks in a short putt to finish with a par. That was a hell of a scramble. 

A round of 68 gives him a share of the clubhouse lead at the halfway stage of his Masters debut. 

Where's that 'thumbs up' emoji when you need it...

The patrons move out of the way on the left side of the 18th green, forming a semi-circle to surround Thomas Pieters as he sizes up his options. He's in a cul-de-sac of people. 

What is he going to do? He is going to knock his chip left onto the top deck, firmly hitting it so the ball circles back round towards the hole.

Seriously. Well played, sir.

Jay Townsend
BBC Radio 5 live at Augusta

Fred is nostalgic, he has done this to us a few other times. It is very difficult at that age to hold it together for four days.

Things get more difficult here over the weekend, the golf course gets more precise. Once you get to that age, your nerves can't hold on for 72 holes. But he knows how to play the golf course as well as anyone and has one of the lowest scoring averages here.

Image source, Getty Images

Fred Couples running out of magic dust as he nears the end of round two. His bunker escape left an outside chance for par but it never looks like being close.

Oh dear.  "Forrrrrrre!" bellows Thomas Pieters. 

The co-leader's no-shot shot on the last spits out of the pine straw, flying to the left of the 18th green where patrons are ducking for cover.

Image source, Getty Images

Adam Scott made seven birdies today but ends just three under for his 18 and level for the tournament. That's a real grind of a round and he deserved a pat on the back. A big pat at the back at that. 

What a response! Rickie Fowler has the second best putting average so far this week - and here's why. A hefty dink from the fringe on 16 finds the centre of the cup. 

We have a new/old co-leader, people.

Phil Mickelson lips out on 14 from four feet. Slippage on the leaderboard.

Speaking of slippage, Fred Couples will have a putt served on a bed of evil for par on 17.

Just when he really didn't want to miss the fairway. Thomas Pieters has landed on nine of the previous 13 fairways today - not the greatest percentage it has to be said - but misses the 18th. 

The Belgian is somewhere in the brown stuff... Not sure if he has got a shot to the green from the trees on the right.

Jay Townsend
BBC Radio 5 live sports extra at Augusta

"I've been around golf a long time, that's the biggest breaking putt I've ever seen. Mickelson was aiming 28ft or so to the right of the pin."

Mickelson should tap in for par from close range on 14.

Justin Rose on 13... eagle... eagle... eagle... no. His ball hangs there and it's a tap-in birdie. The eagle putt from 15ft looked good until the last second.

Image source, Getty Images