Min Woo Lee and Cam Davis hung tough in horrendous conditions before faltering on the back nine to each post one-over-par 71s at the beauty and the beast that is Oak Hill Country Club on Saturday.

Lee is the best placed of the Aussies in a share of 10th alongside four Europeans and an American at one-over-par, the group seven shots in arears of solo leader Brooks Koepka, who is chasing his fifth major title and third in the state of New York on Sunday.

The West Australian, tied with Tommy Fleetwood, Shane Lowry, Victor Perez, Stephan Jaeger and Eric Cole, needing to match, or better, Justin Thomas's all-time PGA Championship final round comeback of last year if he is to win the year's second men’s major.

Davis was a further shot back at two-over as the game's best players were forced to battle through driving rain that made for thick, damp rough and left balls squirting off wet club faces even on the fairways.

Lee and Davis shared sixth at the prestigious Players Championship two months ago and the two young guns again made inspired charges on Saturday to raise hopes of a famous Australian victory.

RIGHT: Davis' day could have been much better if not for a bogey-bogey finish but he is on track for a best major finish. PHOTO: Andy Lyons/Getty Images.

Lee drained a 43-foot putt for his third birdie of the day on the par-4 11th to pull within four strokes of the lead – and just two of equal second having gone through the turn in even par.

But after fighting his driver during the day, the 24-year-old lost his ball off the tee and racked up a double-bogey seven on the par-5 13th and eventual one-over back nine and 71 total shots on Sunday.

“Good grind out there. Let's finish strong,” Lee wrote on his Instagram after the round.

Davis upstaged his superstar playing partner Dustin Johnson by three shots, but will rue three-putting the last, including a missed two-footer, after also making bogey on No.17 in a deflating bogey-bogey finish to an otherwise great round.

The former Australian Open champion putting together a very tidy round of just one bogey against two birdies until the penultimate hole and sharing 16th heading into the final round and looking like improving on his best major finish, which was previously a tie for 39th at the 2018 Open Championship.

Playing in the worst of the conditions, Open Champion Cameron Smith ground out a superb even-par 70 to remain at four-over, but 10 shots off the pace in a tie for 27th at the conclusion of play.

“Good grind out there. Let's finish strong." - Min Woo Lee.

Adam Scott recorded a second straight 74 to be six-over, the par-4 18th again getting the better of the Queenslander who mixed seven bogeys with three birdies on Saturday.

Scott is level with Victorian Lucas Herbert, who had an impressive inward half of two-under 33 to record a third round 72 and share of 42nd with Scott and eight other players, including World No.1 Jon Rahm.