The Sydneysider shot a four-under 66 second round at TPC River Highlands in Connecticut on Friday following his opening 65.

He's tied with Americans Patrick Cantlay (67), defending champion Harris English (65), Nick Hardy (64) and Kevin Kisner (64) at the halfway mark.

But the man they all have to catch is Schauffele who posted a second straight 63 to take a five-stroke lead at 14-under.

The Olympic champion shot a 31 on the front nine with four birdies, then had a 32 on the back, making birdies on 11, 14 and 17.

He has hit 33 of 36 greens in regulation and is the only player in the tournament without a bogey.

Davis got off to a hot start in his second round, making five birdies on the front nine as he seeks a second PGA Tour victory following his breakthrough triumph in the Rocket Mortgage Classic almost a year ago.

First-round leaders Rory McIlroy and J.T. Poston followed opening 62s with 70s to drop six strokes back of the leader.

Schauffele, played one group ahead of McIlroy, who was still leading by a stroke at 13-under before getting into trouble on the 12th hole.

McIlroy hit his tee shot left and out-of-bounds into the woods, then found the deep rough to the right on his next shot. He put the ball into a green-side bunker from there, then chipped out short of the green and into the rough again, before finishing with a quadruple bogey.

The last player to make a quadruple bogey and go on to win a PGA Tour event was Adam Scott at the 2016 Honda Classic. Scott put two shots in the water on the par-3 15th hole.

The cut was set at two-under, with Australians Marc Leishman (even), Brett Drewitt (one-over) and Jason Day (five-over) joining 2017 winner Jordan Spieth (one-over) in dropping out.