The 22-year-old carded rounds of 65 and 70 to finish nine under overall, one clear of American John Hahn.
He told golfweek.com: "Patience really helped me today [Wednesday]. It's a tough finish; it's easy to make bogeys coming in. (You) just have to stay patient.''
The was one of 11 qualifying events to take place in the US on Monday.
Scot Russell Knox made it through at the Woodmont Country Club in Maryland thanks to rounds of 65 and 67. Former champion Lee Janzen was disqualified from that event for using metal spikes.
Kevin Sutherland and Jerry Kelly were among the qualifiers to emerge from Colonial, Memphis, while in Colombus, Ohio, Charley Hoffman was the winner, wiht Swede Robert Karlsson, Australian Aaron Baddeley and South Africa's Rory Sabbatini also progressing.
In total, 55 players booked their places in the main field on Monday.
The US Open takes place at Merion Golf Club in Ardmore, Pennsylvania, from June 13-16.