ROCHESTER (AFP) — Four-time major winner Brooks Koepka shrugged off rain-soaked conditions and boos from spectators Saturday to fire a second straight four-under par 66 and grab a one-stroke lead at the PGA Championship.

Koepka, among US stars who jumped to the Saudi-financed LIV Golf League from the PGA Tour, sank a 47-foot putt at the par-4 17th hole for his fifth birdie to finish on six-under 204 at soggy Oak Hill.

"I putted pretty well and I was pretty happy with my game," Koepka said. "It was tough with the rain, moisture on the greens slowing them up. But I felt like I was a lot more aggressive than I was the two previous days on the greens."

That was good enough for a one-stroke ahead over Norway's Viktor Hovland and Canadian Corey Conners, with LIV's Bryson DeChambeau fourth on 207. All three shot 70 on Saturday.

Koepka and DeChambeau, high-profile players in the PGA Tour-LIV split, were booed by the crowd when they were introduced on the first tee. But both turned jeers into roars with spectacular shotmaking.

'I putted pretty well and I was pretty happy with my game.'

"I love when the fans are on you, cheering for you, or giving you crap if you screw up," Koepka said. "That's the beauty of it. I want that atmosphere."

After a day-long deluge, Koepka birdied the par-5 fourth and par-3 fifth, took his lone bogey at seven, then sank birdie putts of 15 feet at 12 and 18 feet at the par-5 13th before his penultimate-hole bomb.

Koepka could join Tiger Woods and LIV's Phil Mickelson as the only players since 1990 to win five majors by capturing a third career PGA crown.

Hovland, ranked 11th, was set to share the lead in quest of his first major title but found a greenside bunker and made bogey at 18.

"I'm playing really solid tee to green, giving myself a lot of easy pars," Hovland said. "Haven't quite made enough putts to get the most out of my game. Hopefully that will change tomorrow."

In his slog across the water-logged layout, Conners made clutch par saves and birdie putts from inside four feet at the eighth and nine feet at the par-3 15th but was undone by a double bogey six at 16.

"It was a really challenging day with the conditions," Conners said. "I kept it out of trouble and played a lot of good shots."

Conners, ranked 29th, is trying to join 2003 Masters winner Mike Weir as his homeland's only men's major champions. He won last month's PGA Tour Texas Open and had his best major finish, a share of sixth, at last year's Masters.

DeChambeau was two-over on the day after a bogey at 13 but nearly drove the 14th green to set up a birdie and made an eight-foot birdie putt at 15.

He wasn't thrown off by his poor reception at the start.

"I don't care. It's not a big deal," DeChambeau said. "They're going to do that no matter what. I appreciate the fans, them doing that to me. I've got no problem, either way. It still was fun today."

Justin Rose, the 2013 US Open champion trying to become the first Englishman to win the PGA Championship since Jim Barnes in 1916 and 1919, shot 69 to share fifth with second-ranked American Scottie Scheffler on 208, four adrift.

Scheffler, last year's Masters champion, would overtake Jon Rahm atop the world rankings with a victory. He could become the first man to win the PGA and Players Championship in the same year since Hal Sutton in 1983.

Four-time major winner Rory McIlroy fired a 69 to stand seventh on 209 with five birdies and four bogeys in a roller-coaster round.

"It hasn't been great. I can play a lot better," said the world number three from Northern Ireland, who seeks his first major title since 2014.

"It's just tough to play in. It's tough to execute in those sort of conditions."

Rahm, last month's Masters winner, fired a 72 to join Jordan Spieth on 216.

Three-time major winner Spieth, who hoped to complete a career Grand Slam with a victory, fired a 71, his low round this week.