OAKMONT (AFP) — Sam Burns outdueled fellow American J.J. Spaun down the stretch to grab a one-stroke lead after Saturday's third round of the US Open, setting the stage for a Sunday showdown at punishing Oakmont.

Burns fired a one-under par 69 to stand on four-under 206 after 54 holes with Australian Adam Scott, the 2013 Masters champion, and Spaun sharing second on 207 and Norway's Viktor Hovland fourth on 209.

Burns, whose most recent win came at the 2023 WGC Match Play, and Spaun each found the right rough at 18 but Burns made the green and two-putted for par while Burns found a bunker and two-putted for bogey.

"I didn't drive the ball as well as I would have liked, but when I got out of position I did a good job of getting myself back in the fairway," Burns said.

“I was able to convert some of those and kept the momentum going. That was key to the round."

Spaun, whose only PGA Tour win came at the 2022 Texas Open, shot 69 and was happy despite the setback at 18.

"This is the best I've played in my career, for sure," Spaun said.

"I'm just happy I'm still within shouting distance — 18 is just a tough hole if you're out of position. Bogeys happen at Oakmont."

Scott, the 2013 Masters champion, birdied three of the last six holes to fire a 67.

The 44-year-old can be the second-oldest US Open winner after American Hale Irwin, who was 45 when he won in 1990. Scott would also have the longest gap between major titles.

"It would be super fulfilling," Scott said.

"I really haven't been in this kind of position for five or six years.”

"But if I were to come away with it tomorrow, it would be a hell of a round of golf and an exclamation point on my career."

Hovland blasted out of a bunker to set up a tap-in bogey at 17, but made bogey from a bunker at 18 to shoot 70.

"I've got a chance tomorrow. If I shoot a low round then anything can happen," Hovland said. "But there's a lot of good players around me. That forces me to play some really good golf."

The four will play in the last two pairings once again on Sunday in a tension-packed final round for the $4.3 million top prize.

Last-group playing partners Burns and Spaun traded the lead all day, a wild early exchange ending when Burns made a tap-in birdie at the fifth to match Spaun at three-under.

Burns sank a seven-foot birdie putt at the par-three 13th but fell back with a bogey at 16. Both birdied the 17th before the closing drama.

Mexico's Carlos Ortiz fired a 67 to stand fifth on level par 210, a stumble at the last hole dooming a bogey-free bid.

Ortiz made the cut for only the third time in 10 majors and has never finished in a major top 50.

"It would be great. Winning any kind of tournament is awesome," Ortiz said. "I'm just going to do my best and hopefully that's enough. If not, that's all I had."

Stars struggled with second-ranked Rory McIlroy making bogeys on three of his last five holes to fire a 74 and stand on 220.

"I was hoping to play better, but I didn't," McIlroy said, calling his tournament "pretty average" so far.

"The name of the game this week is staying patient," McIlroy said.

"But it's one of those golf courses that you can lose patience on pretty quickly."

Northern Ireland's McIlroy, who completed a career Grand Slam by winning the Masters for his fifth major title, had bogeys on the third and ninth holes, followed a birdie at 10 with bogeys at 11, 14 and 16 and closed birdie-bogey.

Top-ranked Scottie Scheffler, who won last month's PGA Championship, fired a 70 to stand on 214.

"I had a hard time getting momentum," Scheffler said.