LOS ANGELES (AFP) — Rickie Fowler and Wyndham Clark shared a one-shot lead over four-time major winner Rory McIlroy on Saturday after a two-shot swing at 18 left them tied atop the leaderboard at the US Open.

Overnight leader Fowler led playing partner Clark by two as they stood on the 18th tee at Los Angeles Country Club.

Clark had just dropped a shot at the 17th, but his approach at the last threatened the pin before leaving him a six-foot birdie putt that he calmly rolled in.

Fowler, who had gone 12 holes without a bogey as a string of rivals faltered on the treacherous back nine, saw his 42-foot birdie putt skim the edge — but his four-footer for par coming back lipped out.

Fowler signed for an even par 70 while Clark posted a one-under 69 that left them one in front of Northern Ireland star McIlroy, who carded a 69 for 201 to remain in position to claim a fifth career major and his first since 2014.

After two days of record scoring, the sun-baked LA Country Club North Course — hosting the championship for the first time — proved plenty capable of providing a classic US Open test of patience and nerve.

Fowler, who had a stunning 18 birdies over the first two rounds, couldn't match those fireworks, his three birdies including a 36-foot putt at the seventh and a 70-footer from off the green at 13.

Clark, a long-hitter who broke through for his first US PGA Tour title at Quail Hollow last month, had grabbed a one-shot edge through nine holes before back-to-back bogeys at the 11th and 12th.

'The golf course definitely got a little bit trickier today than the first couple of days.'

Unable to get up and down from a greenside bunker at the par-three 11th, Clark then botched his first attempt to chip out of greenside rough at the 12th.

He rebounded with a birdie at 13, but it looked as if he'd be chasing on Sunday after his second shot at 17 found the barranca right of the green.

McIlroy had three birdies and two bogeys and was rarely in real trouble.

"The golf course definitely got a little bit trickier today than the first couple of days," McIlroy said. "Felt like I played really smart, solid golf."

"Hit a lot of fairways, hit a lot of greens. Sort of felt somewhat stress-free out there, if you can ever call golf at a US Open stress-free."

World No. 1 Scottie Scheffler was alone in fourth after a 68 for seven-under 203.

Scheffler, the 2022 Masters champion who started the day five adrift, picked up three strokes in the last two holes.

Coming off his fourth bogey of the day at the 16th, Scheffler holed out from 196 yards out in the fairway for eagle at the 17th then drilled a 22-foot birdie putt at the last.

"I was fighting all day today, trying to just get myself back in position," Scheffler said. "Just trying to make some birdies and avoid the bogeys."

"Today it seemed like every time I got off line I was really fighting for par — just fortunate to see that shot go in on 17 and then a nice birdie on 18 to kind of get myself back into it."

Scheffler was one stroke in front of fellow American Harris English, who was one off the lead after his fourth birdie of the day at the 10th but had four bogeys the rest of the way in a one-over 71.

Two-time major winner Dustin Johnson and 2021 Olympic champion Xander Schauffele shared sixth on five-under 205, one shot in front of Japanese qualifier Ryutaro Nagano, who posted a 68.

It was a further stroke back to reigning British Open champion Cameron Smith of Australia, former US Open champion Bryson DeChambeau and South Korean Tom Kim on 207.