Champion: -14 Thomas
-13 Westwood; -12 DeChambeau, Harman
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Tournament being played at TPC Sawgrass in Florida
Alex Bysouth and Peter Scrivener
Westwood -13 (15)
Lee Westwood hits a tracer bullet of a shot for his second on the 16th. It's not a great finish, in the sand well short of the green and it looks like he's going to be hampered by a couple of trees a few yards in front of him
Thomas -14 (16)
How's the nerves JT? Firm and straight in the middle. Big putt that moves the American one clear again.
There's a decent walk from the 16th green to the 17th tee, Plenty of time to consider how you're going to play the hole.
Thomas -13 (15)
Justin Thomas is on the 16th green after two excellent blows. He's 47 feet from the hole and facing a curling downhiller.
Terrific lag putt to about three feet. That's about the same distance as he missed for par on the 14th though...
Westwood -13, DeChambeau -10 (15)
Back on the 15th and Lee Westwood is standing over a four-footer for par after being a touch aggressive with his third shot from just short of the green.
It's downhill. Westy sets the ball off on the left edge of the hole and it curls beautifully into the centre of the cup. He saunters off the green with his tongue hanging out.
He's loving this.
Bryson DeChambeau is in for par. Three shots to make up in the closing three holes.
That could soon be four though...
B Harman -12 (17)
About 20 minutes ago, I said you'd be a fool to take on the pin at 17. Well, Brian Harman has just left me with egg on my face. The left-hander is in need of a birdie and he plonks his ball a yard onto the green and the ball settles eight feet from the hole.
Can he finish the job? Yes he can.
Can he get one more on the last and nick this?
Casey -11 (16)
Paul Casey is refusing to go away quietly. A lovely curling birdie putt on the 16th lifts him to within two of the top.
Westwood -13, DeChambeau -10 (14)
The smile that has been across Lee Westwood's face all week momentarily disappears after his approach to the 15th from a fairway bunker pulls up short of the green and dribbles backwards.
Bryson DeChambeau, from the other side of the fairway, in the pine straw, powers a wedge into the heart of the green.
One hole ahead, Justin Thomas is hitting a belter right down the middle of the 16th.
Right, time to settle in for the business end of the tournament. Where's your money now folks?
Thumbs up for Westy. Thumbs down for JT.
-13 J Thomas (15), L Westwood (14)
-11 T Gooch (F), B Harman (16)
-10 C Conners (F), M Fitzpatrick (16), P Casey (15), B DeChambeau (14)
Thomas -13 (15)
What can Justin Thomas do on the 15th. No dramas. A straightforward two-putt par.
Big birdie chance coming up though. The par-five 16th has been the 16th easiest hole today...
Westwood -13, DeChambeau -10 (14)
Fist-pump from Lee Westwood, he's back into a share of the lead!
The 47-year-old is all smiles after coaxing a birdie putt down the slope from seven feet and into the heart of the cup. He's applying the pressure.
Bryson DeChambeau can't follow suit. He bogeys to fall three back.
-10 Fitzpatrick (16)
Matt Fitzpatrick is on the 17th tee. Gap wedge in hand. 133 yards to the hole, which is nestled back right. Only the foolish would chase that pin.
Fitzy plays the sensible shot, heart of the green. Devilishly difficult putt coming up, mind.
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-13 Thomas (14)
"Agghhh, it's such a bad break," says Justin Thomas after clipping his ball from the first cut onto the 15th green.
The American was referring to his tee shot running out of fairway which meant he was unable to put spin on his second and his ball skips 20 feet past the hole.
Westwood -12, DeChambeau -11 (13)
Oh, Lee Westwood!
The Englishman gets a huge slice of luck to avoid the water at 14, instead nestling in the sand, and hacks his approach up on to the smooth stuff for an excellent look at a birdie. Wonderful shot.
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Fitzpatrick -10 (16)
And here comes Matt Fitzpatrick. If ever a player was battling along knowing they've not had their A game this weekend, it's the young Englishman.
A birdie on the par-five 16th and he's back to double digits under par. He's going to need a birdie-birdie finish you feel.
Exciting eh?!
Thomas -13 (14)
When Justin Thomas finds the middle of the fairway he usually goes pin-seeking. Not this time. His ball flirts with the bunker down the left but stays on the 14th green.
Just the 70 feet across the green. That's three-putt territory for us mere mortals. JT knocks it to three feet.
Simple par...NO! It lips out. He's dropping a shot.
Gooch -11 (F)
Talor Gooch is on the 18th green in two. Can he roll in the 15-footer?
No. That's weak. Pulls up a foot short. But, we have a new clubhouse leader folks
Westwood -12, DeChambeau -11 (13)
Bryson, Bryson, Bryson... he's hanging on in there. A lovely tee shot from the world number six at 13 and he wriggles in a second successive birdie from eight feet.
Lee Westwood ticks off another par.