South African Oosthuizen, who won the 2010 British Open, started the day four strokes off the pace but his hopes of landing a second major quickly faded and he finished a distant eight shots behind DeChambeau in third place.

“Finishing third in a major is always great (but) it was going to be tough,” the 37-year-old told reporters after signing for a two-over 73.

“Bryson is playing his own little golf course at the moment. This golf course definitely showed its teeth today with the firmness of the greens and the fairways and the wind, and it was just tough.”

While Oosthuizen struggled in the conditions, DeChambeau ramped up his power game to romp to a final-round 67 and victory by six shots over fellow American Matthew Wolff

“I think he’s busy setting his own little way of playing,” Oosthuizen added.

“He’s hitting it so far. He’s so strong out of the rough and he’s probably one of the best putters out there. (In) a week that he really putts well, you’re going to have a lot of trouble.

“It’s great to see. Hats off to him for what he’s doing. He went out on this journey, and he’s pulling it off. He’s playing great golf.”

Oosthuizen said even without DeChambeau’s magnificent final round he would still have struggled to land his second major on the daunting layout.

“If you take him out, I’m right up there,” he said.

“But you know, if you take him out, then probably a little bit more nerves and stuff coming down the stretch, so there’s a lot of things that could go different then.”

(Reporting by Amy Tennery, writing by Nick Mulvenney in Sydney, editing by Peter Rutherford)