Lipscomb University junior Dawson Armstrong, 20, of Brentwood, Tenn., fired a 6-under-par 64 Monday to hold the lead after the first round of stroke play in the 116th U.S. Amateur Championship at Oakland Hills Country Club’s North and South courses.

“I'm actually a little more excited about just a personal goal,” Armstrong said. “I've shot a lot of 65s but I've never shot 64 in a tournament, so it feels really good to finally reach that hump.”

The 2015 Western Amateur and Dogwood Invitational champion posted seven birdies against one bogey on the North Course to hold a one-stroke lead over Gavin Hall, of Pittsford, N.Y.; Robin Petersson, of Sweden; and Alex Smalley, of Wake Forest, N.C.

Armstrong, who played in the Amateur in 2014 and missed the match-play cut, credited his growing experience as a catalyst for his performance.

“Obviously, the level of success has changed over two years having experience in winning, but I could feel myself last night and the night before just telling myself, all right, if we just get to match play, if we just get to match play,” Armstrong said. “But I just kind of stood back and said, let's try to play well and try to win stroke play. It's tough to do.”

Playing in his first USGA championship, Petersson, 24, posted seven birdies and two bogeys on the North Course.

“I'm really excited I pulled it off,” said Petersson, who played for Europe in the 2016 Palmer Cup. “I think the U.S. Amateur is the best amateur event in the world, and where I'm at right now, it feels pretty good.”

A 2016 graduate of Augusta (Ga.) University, where he earned honorable-mention All-America honors and was a two-time MEAC Player of the Year, Petersson made his move on the inward nine.

“The first few holes on the front nine out here, I just had perfect numbers on a five-hole stretch,” Petersson said. “I just fired right at it, and I was close, and I was able to make the putts. It's as easy as that.”

Smalley, 19, a sophomore at Duke University, fired a bogey-free round on the North Course. As a freshman in 2016, he earned All-Atlantic Coast Conference Academic honors and won the 2016 Princeton Invitational.

“I think I hit all 18 greens today,” Smalley said. “I didn't put any stress on any parts of my game. I was pretty consistent all day, and just hit good shots all the way around.”

Hall, a 21-year-old senior at the University of Texas, had a clean scorecard with five birdies, four coming on his inward nine.

“Any time you can be bogey-free in a USGA event, it's pretty good,” said the left-handed Hall. “I'm happy with the way I played. This course is really gettable, especially with the conditions out there.” 

A group of six players, including Sam Horsfield, 19, of England, fired 4-under-par 66s on the North Course to trail Armstrong by two strokes.

Joining Horsfield, ranked No. 2 in the World Amateur Golf Ranking™, at 66 were 2015 U.S. Mid-Amateur runner-up Marc Dull, 30, of Winter Haven, Fla.; Cristobal Del Solar, 22, of Chile; University of Texas junior Taylor Funk, 20, of Ponte Vedra, Fla.; University of North Carolina junior Ben Griffin, 20, of Chapel Hill, N.C.; and Auburn University junior Ben Schlottman, 20, of Winston-Salem, N.C.