Peter Scrivener
BBC Sport at TPC Sawgrass

The par-four 12th was remodelled a few years ago to try and tempt players to go for the green in one.

Pete Dye, who designed the original course, reluctantly agreed - his argument being if he wanted one shot to the green, he builds a par three.

Paul Casey is not giving in to temptation.

He lasers an iron down the fairway.

But now we have a lengthy pause because Cam Smith is out with the big dog and eyeing this up.

All 295 yards of it.

The group in front are still on the green though...

Dare I even suggest that the possibility of a a first play-off since 2015 looms large?

Image source, Getty Images

Everyone loves a downpour don't they? Ahem. Not sure it does Viktor Hovland too much good over on the par-four15th ind.

The 24-year-old takes three putts and coughs up a stroke to drop back into a tie for fifth.

The long-time leader Anirban Lahiri has not given up just yet. He basically takes the same line as Casey over on nine with exactly the same result. Birdie.

Share of the lead. Again.

Paul Casey lands his second 65 yards from the pin then drops his chip to six inches. Six inches. The Englishman's short game really is exemplary.

Cameron Smith has a four-foot putt for birdie mind, and he reclaims the lead. That opening line aged well.

Peter Scrivener
BBC Sport at TPC Sawgrass

Paul Casey summons an official on the 11th green. “There’s casual water on the green,” he says. “Someone’s on their way,” he’s told.

“We need a squeegee,” says Casey.

Although the rain has abated. It’s like someone’s turning a shower head on and off above the course.

Over on the 11th Paul Casey is plotting is next move and his approach into the green from the refuge of a rather large golf umbrella.

The sort I clumsily try to get through the school gates dropping off the kids before realising i'd have been better off with a big hood.

It is absolutely nailing down at TPC Sawgrass now. I hope you have the waterproof Peter?

The weather is definitely not going to improve the mood of Justin Thomas, who moments after making eagle fires his tee shot into the drink on the 17th and then finds the bunker from the drop zone. Ouch.

Cameron Smith does indeed make an inevitable birdie on the 10th to share the lead with Keegan Bradley, who makes a fourth straight birdie on the 12th, rattling in an eight footer.

That hole has to go down as a win for Paul Casey mind, who saves par courtesy of a sublime chip and nerveless putt.

Justin Thomas deserves that round of applause. The defending champ hasn't entirely given up hope yet and takes an eagle on the 16th.

Battling round this.

Cameron Smith is trying to compose himself and get himself back on track over on the 10th...

And playing a 155-yard iron shot into less than a foot means an al most certain birdie is on the way.

Paul Casey's second buries itself in the green-side bunker after a poor tee shot saw him wander off to the rough on the right.

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Was Keegan Bradley in the sand on the 11th or just on the verge of the hole-side bunker?

It matters not. A delightful clip into 12 feet sees him produce another birdie to sit in a three-way tie for the lead.

Peter Scrivener
BBC Sport at TPC Sawgrass

Cam Smith played military golf down the ninth and his putting touch has gone too.

This has turned into a proper wobble now.

The wind is picking up and that four-birdie start seems a long time ago.

Paul Casey, meanwhile, is doing what he said he would do. Fairways and greens. Keeping it simple.

And suddenly, from four back he’s sharing the lead.

It’s quite a trek from the ninth green to 10th tee, behind the back of the 18th green and a couple of hundred yards from there.

Plenty of time for our leaders to think about the state of play.

What a turnaround. Paul Casey plays a superb iron shot down the ninth and gets his reward with a deft chip that gives him a gimme birdie.

Cam Smith makes a third straight bogey after, to be honest, a pretty awful putt to save par.

Casey takes a share of the lead.

Anirban Lahiri says 'it's okay' as he walks off the eighth green with a double in his back pocket. He's back in a tie for third.

Keegan Bradley has been round the block a bit since he won the 2011 PGA Championship.

There are not too many W's next to the American's name but a birdie on the 10th sees him move just two behind the leaders.

Cameron Smith started like a train but there are just a few signs that he is not quite at it now.

Back down the eighth Anirban Lahiri is taking a drop after going miles left. Zero view of the green and a huge set of trees in front of him.

He'll do well to escape with a double.

Yikes what is that? It's so sloppy from Viktor Hovland who duffs his chip through the 12th green and sees it run off towards the water.

It stops short but he's faced with two really tricky shots to scramble to a par, which he can't do.

Hovland is muttering away to himself about being poor at chipping, a tad harsh given he could be world number one after this event.

It's the hope that kills you. Paul Casey goes left off the tee but seems to recover with his pitch before sliding his par-saving putt right. The Englishman's first dropped shot of the round.