NEWTOWN SQUARE (AFP) — Alex Smalley overcame a horrid start with seven birdies in the last 12 holes to seize a two-stroke lead after Saturday's third round of the PGA Championship.

The unheralded 29-year-old American, chasing his first PGA Tour title in only his fifth major start, fired a two-under-par 68 to stand on six-under 204 after 54 holes at Aronimink with an epic Sunday showdown in store.

A congested leaderboard saw 14 players atop the field at some point Saturday, with 21 players finishing within four strokes of Smalley — eight of them major champions.

"Looking forward to tomorrow," Smalley said.

 "It's going to be a difficult day. It's something I haven't experienced before. Certainly there are going to be a lot of thoughts going through my head."

Smalley made bogeys on three of the first four holes, then bounced back with four birdies in the last six holes, including a 27-foot putt at 15 and a 13-footer at 18.

"It was tough. It was windy. Wasn't giving myself a lot of good looks or even making the green at all," Smalley said. "Was lucky to be three-over after six. Steadied the ship after that."

Jon Rahm, the 2021 US Open and 2023 Masters champion, closed with a bogey to shoot 67 and join a second-place pack on 206.

"I'm not overly surprised," Rahm said of the packed leaderboard. 

"It's an extremely difficult golf course... you have to play really good golf to give yourself a chance out there."

Germany's Matti Schmid and Canada's Nick Taylor, who each fired 65, and England's Aaron Rai, who also shot 67 after a closing bogey, were also on 206, as was Sweden's Ludvig Aberg.