ST. SIMONS ISLAND, Ga. (AP) -- Kevin Kisner had a 6-under 64 on Saturday to build a three-shot lead in the RSM Classic as he goes for his first win on the PGA Tour.
Already a runner-up four times this year - three in playoffs - Kisner has never had a chance this good.
Kisner made his only bogey of the round on No. 14 and failed to make birdie on the par-5 15th to fall into a tie for the lead with Kevin Chappell. He answered with a key shot that set up birdie, a 6-iron into a foot at the par-3 17th and a 30-foot birdie on the 18th to build some separation.
Kisner was at 16-under 196, a record 54-hole score at Sea Island.
Chappell overcame back-to-back bogeys early in his round for a 68. He also is going for his first PGA Tour win.
Graeme McDowell survived a mental blunder on the opening hole and was four shots back with a chance to win back-to-back on the PGA Tour. On the first fairway, he lifted his ball to clean it when he realized that for the first time this week at Sea Island, conditions no longer allowed for lift, clean and place. McDowell was penalized one shot and made a 10-foot putt that became a par with the penalty.
He had his caddie carry the tees in his bib so he wouldn't make the mistake again. And that was the last mistake on the golf course, as the former U.S. Open champion again kept the ball in play off the tee and made his share of putts for a 65.
Even so, it starts with Kisner and his last chance to win in the final round of the year on the PGA Tour.
"What I've learned is you just can't hold back on this tour," Kisner said. "Any time you think you're doing great, somebody else is, too. I'm just going to try to keep making birdies. I'll put a number of 20, 21 (under) in my head and see if they can catch that one."
Alex Ceja had his third straight 67 and was the only other player within five shots of the lead.
Kisner took the lead for the first time with a birdie on the par-4 fifth hole and he had a two-shot lead until his bogey on the 14th and Chappell's birdie on the 15th.
"Standing on 15, I was thinking it was going to be a dog fight all day tomorrow again, which it will," he said. "But having a three-shot cushion was huge to finish that way. Sixteen is not my favorite tee shot in the world, that left-to-right wind, so to have a really gone and birdie there was clutch."
The other two birdies made it better.
This is the first time Kisner has had the 54-hole lead on the PGA Tour - he was tied with Russell Knox going into the final round in Shanghai two weeks ago at the HSBC Champions, where Knox won by two shots.
Chappell bounced back from his bad start with five birdies, feeling that his round could have gotten away from him. The concern for Sunday was as much the three-shot deficit as the guy in the lead.
"He's been in this situation a lot lately, and it will probably take a low one from me tomorrow to have a chance," Chappell said.
McDowell is the only one feeling as though he is playing with house money. His game was in full reverse this year until he slowly began turning it around, and he won Monday in the OHL Classic at Mayakoba. "A big weight lifted off my shoulders," McDowell said.
The victory gave him a sense of freedom, and that's how he's swinging the club. As for the penalty on the opening hole?
McDowell was used to it. He said there were preferred lies at the British Masters and European Open, and part of the time in Hong Kong and all but one day in Mexico.
"I literally just got into automatic pilot mode in the first fairway," he said. "Before I realized that, Michael Kim is looking at me funny. I'm like, 'OK, I just picked this ball up.' What an idiot. ... It was a big 4, and it makes for a better story at the end."
DIVOTS: Kyle Reifers also was guilty of picking up his ball in the fairway think conditions were lift, clean and place. The difference? Reifers did it on his ninth hole of the day. ... Fifteen players missed the 54-hole cut, including British Open champion Zach Johnson. ... Tournament host Davis Love III shot a 69 and was 13 shots behind.