Compatriot Cameron Tringale and Canada's Adam Hadwin carded six-under 66s to share second place at Silverado Resort and Spa's North Course while reigning Masters champion Hideki Matsuyama (69) of Japan is tied for 24th.

Marc Leishman is the pick of the Australians after also shooting three-under while Lucas Herbert, Cameron Percy and Aaron Baddeley are two shots further back after their 71s.

Reigning PGA Championship winner Phil Mickelson (70) and reigning U.S. Open champion Jon Rahm of Spain (72) are within striking distance.

Reavie, who began on the back nine, logged eight birdies and four pars over his final 12 holes, closing with three consecutive birdies.

"It was kind of a slow start, but I told myself to stay patient, you have plenty of chances to make birdies and I was able to do that coming in," he said.

"But I was one over through six holes, I think. I was like, 'OK, stay patient, don't become impatient.' Yeah, fortunately I was able to make some birdies."

Reavie, 39, owns two career PGA Tour wins, at the 2008 RBC Canadian Open and the 2019 Travelers Championship while Tringale is looking for his first PGA Tour victory and Hadwin just his second.

Rahm, who is ranked No.1 in the world, is the only player in the field who will compete at next week's Ryder Cup.

"Not my best ball-striking day, a little tight today probably from having to be in bed for so long yesterday," Rahm, who was still feeling the effects of a stomach ailment that forced him to withdraw from the pro-am Wednesday, said.

"Even with how I felt, I played a little bit better than I thought I was going to, to be honest. Started great, started to hit some good shots, too bad I couldn't capitalise on some of the good chances early on."