PATRICK CANTLAY DRAINED a 23-foot birdie putt at the 18th hole to stretch his lead to two strokes over top-ranked Jon Rahm on Saturday at the US PGA Tour Championship.

Cantlay, who led by four strokes through 10 holes, survived a rough patch that featured three bogeys in six holes on the back nine, carding a three-under-par 67 at East Lake in Atlanta, Georgia.

He was 20-under for the tournament, which featured a staggered start that awarded strokes to each player based on their places in the FedEx Cup playoff standings.

Rahm, who started the event four strokes behind Cantlay, had three birdies and a bogey in a two-under 68 that put him at 18-under par.

American Justin Thomas, the 2017 playoff champion, matched the low round of the day with a five-under par 65 to stand alone in third on 15-under par.

Cantlay said his closing birdie was “big for momentum” as he chases the title and $15 million jackpot for the winner of the playoffs.

“It was a nice putt to make, especially being out of position on that hole,” he said. “And I’ll take that momentum into tomorrow.”

Cantlay was on fire on the greens early, capping his three birdies on the front side with a 30-footer at the ninth that put him three ahead going into the back nine.

He added a nine-footer at the 10th to stretch his lead to four shots at 21-under.

But he bogeyed the 11th, unable to make an eight-footer to save par. After a clutch six-foot birdie at 13 — where Rahm had made a 26-foot birdie — he bogeyed 14 and 16 to see his lead dwindle to one stroke.

“I thought I rolled the ball on the greens just as good as the last couple days, and my speed was good, and a few putts went in today which was nice,” Cantlay said. “So I feel like I’m in a good spot going into tomorrow, and that putt on 18 put the momentum in the right direction.”

Alamy Stock Photo Alamy Stock Photo

Rahm said the round was “not my best.

“Great off the tee, I must say. Man, hitting it really good off the tee. Just wasn’t as sharp as I wanted to be with my irons,” the Spaniard said.

Rahm said he found himself between clubs a lot, leaving him “a lot of three-quarters and finessing around, and certain holes I just played a little bit more conservative, and didn’t give myself the best chances to make putts.

“But I hung in there, gave myself a couple chances down the stretch.”

He said he didn’t feel panicked when Cantlay pulled away early.

“Listen, it could happen that he could keep up that play, but it’s very unlikely,” Rahm said. “I knew sooner or later at some point he was going to stop.”

“I think a key moment was me making that putt on 13, me making the putt and feel like I stole one and him missing the tee shot on 14, that’s where things got a little bit closer.

Cantlay said, as he has all week, that he’ll try to treat Sunday’s final round like any other, and not focus on the bumper multi-million dollar payday that is within his grasp.

“The internal drive to win golf tournaments is really what drives me, and so the external factors are not as much of a factor for me,” he said.

Rahm said he was looking forward to a last-group duel with Cantlay — but he wasn’t discounting Thomas.

“I like going head-to-head with anybody,” he said. “It’s pretty cool that a whole year race technically is ending tomorrow, and not that we separate ourselves a lot, because J.T. had a good round today, but if we keep playing the way we have, unless somebody posts a really low score out there, hopefully it will be a good show down on the back nine with me and Patrick.

“Hopefully I come in with my A Game and guns blazing.”