Maverick McNealy capped a wild eight-under par 64 with a chip-in eagle to grab the halfway lead in the US PGA Tour Fortinet Championship, where world No. 1 Jon Rahm missed the cut.
Along with his eagle at the par-five ninth hole, McNealy had nine birdies and three bogeys at Silverado Resort in Napa, California, for a 12-under par total of 132.
"It was crazy," said the Northern Californian, who played his first nine in five-under then opened his second nine with three straight bogeys.
He followed that with four birdies in a row, rolling in a nine-footer at the fourth, a four-footer at the fifth and another nine-footer at the sixth before holing out from a greenside bunker at the seventh.
After his "flawless" first nine, McNealy said, chance played a role in his next-nine struggles.
"I got to the first hole and funny lie in the right rough and dumped it in the bunker and shanked the bunker shot, got up and down for bogey and then bogeyed the next two," he said. "I was kind of going, oh, man, this is going the wrong way quick."
He turned it around however, and after chipping in from 74 feet short of the green at the ninth he heads into the weekend with a two-stroke lead over Beau Hossler, who also carded a 64, and Chile's Mito Pereira, who signed for a 67.
"It's great to be at the top of the leaderboard now," said McNealy, who is in search of his first US PGA Tour title. "But it means a heck of a lot more to be at the top at the end of 72 holes."
That prospect ended for Spain's Rahm with a one-under par 71. His one-under total of 143 left him two shots outside the cutline and gave him what could be a useful weekend off as he prepares to play for Europe in the Ryder Cup at Whistling Straits next week.
- Not 'best' Rahm -
Rahm insisted there was no serious cause for concern with his game with the match play showdown between the United States and Europe looming.
"It's very simple, not my best ball-striking-wise," he said. "Still wasn't bad. Could have been better on the greens, you know. Feel like I might have made a couple of mistakes mentally on some approach shots, maybe I could have focused a little more, visualized better, but I think I left a lot of shots on the greens."
Rahm had hoped tournament play in the first event of the US PGA Tour's 2021-22 season would keep him sharp heading into the Ryder Cup.
His week didn't go according to plan, however, as he found himself battling a stomach bug that prompted him to pull out of Wednesday's pro-am.
"Well, I've got two more days off. I think it's primarily rest. I feel like with having those stomach issues early, I wasn't nearly as rested as I could have been, my body got a little bit tight, but I'm feeling good today.
"It was a tough course out there. If anything, I get to rest a couple extra days and be able to figure out what's going on with my swing, which technically is not really anything bad. It's just I think a lot of those swings were made to look worse because of how tough it is out there."