Xander Schauffele and Patrick Cantlay combined for a 13-under-par 59 in the four-ball first round of the Zurich Classic of New Orleans, the only two-man team event on the PGA Tour.
The US duo had a one-shot lead over fellow Americans Matthew NeSmith and Taylor Moore at TPC Louisiana in Avondale.
FedEx Cup champion Cantlay and Tokyo Olympic gold medallist Schauffele thrived in breezy conditions, seizing the lead with a record-setting score.
Schauffele, owner of four PGA Tour titles, had six birdies and Cantlay had an eagle and five birdies as they powered to the top of the leaderboard, Cantlay draining birdies at 17 and 18 to cap the round.
Cantlay said he “wasn’t really thinking about 59” when he rolled in his birdie putt from less than four feet at the last, because of the four-ball format.
“Just trying to make a birdie on par-five like every other week,” he said.
But Schauffele said that even though a sub-60 round in the two-man format might not carry the same cachet as an individual 59 he still considered it an achievement.
“It counts for me,” he said. “I haven’t done it before. I don’t think Pat has either. I’ll count it in my book.”
Cantlay said he thought Friday’s second-round foursomes format would help them keep the momentum going.
“I think Xander and I really like alternate shot,” he said. “It’s one of our strengths for the week, and we’re really looking forward to it,” he said.
NeSmith and Moore matched the previous course record with their 60, briefly taking the lead after England’s Aaron Rai and American David Lipinski took control early with a 61 highlighted by Lipinski’s eagle on the eighth hole.
They were joined on 61 by Tommy Gainey and Robert Garrigus, and Doc Redman and Sam Ryder.
In his first start since winning The Masters, world No 1 Scottie Scheffler teamed with Ryan Palmer to shoot an eight-under-par 64.
Defending champions Cameron Smith and Marc Leishman of Australia opened with a 65.