American Justin Thomas will take a three-shot lead into the final day of the WGC-Bridgestone Invitational after producing a stunning 67 on a day of tougher scoring at Firestone Country Club.
With the course firming up throughout the afternoon, the scoring average soared on day three but halfway co-leader Thomas seemed unfazed, mixing six birdies with three bogeys on Saturday to get to 14 under par.
He has a star-studded chasing pack breathing down his neck, however, with 2014 champion Rory McIlroy and Ian Poulter in a tie for second on 11 under.
McIlroy posted a bogey-free 67, with his birdies coming at the second, ninth and 17th, while Poulter's 70 was made up of four birdies and as many bogeys.
Australian Jason Day was another shot back on ten under after his third-round 69, which included a chip-in birdie at the short 15th.
World Number Three Thomas, who will defend his US PGA Championship title at Bellerive Country Club next week, began the day alongside Englishmen Poulter and Tommy Fleetwood but took the outright lead when he opened his birdie account from four feet at the long second.
He dropped shots at the third and fifth to fall three strokes off the pace set by Poulter, who got off to a fast start with birdies at the second and third.
Thomas bounced back with a birdie from six feet at the sixth before making another gain at the eighth to get back to 12 under.
And after Poulter carded his first bogey of the day at the seventh, Thomas regained the solo lead with a birdie from close range at the tenth.
Thomas chipped in from just off the green to pick up another shot at the 12th before notching his sixth birdie of the day from ten feet on the 14th to move to 15 under.
Ryder Cup star Poulter bounced back from dropping his second shot of the day at the 13th with a fine birdie from 21 feet at the next to reduce Thomas' advantage to three shots.
His lead was cut to two when the 25 year old failed to get up and down from a bunker at the short 15th.
But with Poulter sandwiching his birdie at the long 16th with bogeys at the 15th and 17th, Thomas was three strokes clear once again.
And Thomas safely parred his final three holes to head into Sunday's final round on 14 under par.
Thomas said: "I played well again today. I didn't get off to the sort of start that I have been over the last couple of days but I made a good birdie on the second after a not very good drive - I got away with one.
"I made a couple of bogeys there on the par threes with a pretty easy bunker shot, so that was a little upsetting. But overall I really, really played well in the middle of the round and made a lot of key birdies.
I just need to go out tomorrow and have a blemish-free round and feel like the field's going to need to kind of chase after me a little bit - Justin Thomas
"I'm in a position where I can play smart (tomorrow), I don't need to play really conservative.
"I mean, if I hit good drives I'm going to have wedges in my hands where I can attack and make birdies.
"But for the most part, I just need to go out tomorrow and have a blemish-free round and feel like the field's going to need to kind of chase after me a little bit, which can be done on this golf course, but it's definitely getting a little firmer and faster."
Marc Leishman and Kyle Stanley were tied for fifth on nine under, one shot ahead of Spain's Jon Rahm and American Rickie Fowler, who made five birdies and no bogeys on Saturday.
