Kevin Kisner produced a battling one over par round of 72 to take a one-shot lead into the final day of the US PGA Championship at Quail Hollow Club.
The American entered Saturday in a share of the lead and on a day of tough scoring in North Carolina he dropped to seven under to lead the way from countryman Chris Stroud and World Number Three Hideki Matsuyama.
Matsuyama started the day as co-leader but signed for a 73, while Stroud recorded a level par round of 71 to sit a shot ahead of South African Louis Oosthuizen and American Justin Thomas.
Kisner has never had a top ten in a Major Championship but on Sunday will be looking to become the second consecutive wire-to-wire winner of the season's final Major in his 20th European Tour appearance.
"I'm happy I'm in the position I'm in," he said. "I had a chance to run away from guys and take people out of the tournament that were four or five, six back and I didn't do it. Now I'm in a dogfight tomorrow and I have to be prepared for that.
"It's a dream to win a Major, that's what I grew up practising and playing for, to play on the PGA Tour and to have a chance in Major Championships.
"The way my game's progressed over my career I like where I am and I like having a chance tomorrow. It will be awesome to take home the Wanamaker Trophy and there are a lot of great names on that trophy."
Matsuyama will be looking to make it back-to-back wins after his triumph at the WGC-Bridgestone Invitational while Stroud was also a winner last week at the Barracuda Championship to claim the final place in the field in Charlotte.
Matsuyama was left with a difficult angle into the first off the tee and dropped a shot and it was almost a two-shot swing as Kisner saw a double-breaker agonisingly graze the hole.
Stroud got to seven under as he holed from 18 feet on the fifth but he gave the shot back as he missed the green on the par three next before taking advantage of the par five seventh.
Kisner then just avoided the water and got up and down for birdie on the same hole, with Matsuyama picking up a shot after getting on in two.
Stroud joined Matsuyama at eight under as he holed from 12 feet on the eighth and the Japanese did well to save par on the ninth after hitting his drive into the trees.
The leading trio then all dropped a shot on the 12th, with Matsuyama surrendering another after missing the green on the 13th before Stroud and Kisner bounced back with birdies on the drivable 14th.
Kisner then got on the par five 15th in two and two putts later he was the first man into double figures and had a two-shot lead.
That would not last long as he found the water on the 16th to record a double-bogey but he had a one-shot advantage when Stroud needed three putts from just off the green to get down on the 17th.
Another bogey followed from Stroud as he three-putted the last and when Kisner failed to get up and down after a poor second, the event was all of a sudden wide open.
Oosthuizen did brilliantly to save par on the second after seeing his tee-shot rest against a tree but looked to have hurt his arm in the process and bogeyed the sixth shortly after having it strapped. He bounced back with a birdie on the seventh but bogeyed the 12th and then went birdie-bogey-birdie before making a smart par save on the last.
Thomas had four birdies and two bogeys in his 69 to sit two shots ahead of fellow American Grayson Murray.
Canada's Graham DeLaet was at two under thanks to a remarkable birdie-eagle-eagle-birdie run from the 13th alongside Francesco Molinari, Patrick Reed, Scott Brown and Gary Woodland.
