Matthew Wolff, a 21-year-old American making only his second major start, fired a five-under par 65 to seize a two-stroke lead after Saturday's third round of the US Open.
The 2019 US college champion for Oklahoma State, who shared fourth at last month's PGA Championship, solved wicked Winged Foot to stand on five-under 205 after 54 holes.
Wolff found only two of 14 fairways but blasted from the deep grass onto 12 greens in regulation and made six birdies against a lone bogey.
"Every time I was in the rough and had a good lie I took advantage of it," Wolff said. "I minimized the mistakes. It was a good day all around.
"I got really fortunate with the lies in the rough. I just stuck with my game. It was a grind out there."
American Bryson DeChambeau was second on 207 after shooting 70. He opened with back-to-back bogeys and closed with a bogey after birdies at 16 and 17.
"I felt like I was trying to hope it into the fairway all day. That's not what you want at a US Open," said DeChambeau. "I was able to show resilience, coming back to shoot par after two bogeys."