It started with an 18-foot birdie putt on the 13th hole. He won the next two with wedges into about 5 feet, and then hit 4-iron to 3 feet on the par-3 16th. Thorbjornsen closed out the match, 2 and 1, with a bunker shot on the reachable par-4 17th had hit the pin and settled 8 feet away.
But the 19-year-old from Massachusetts was in trouble late in the second round against Nick Gabrelcik, who birdied the 15th and 16th holes before the storms arrived. Gabrelcik was 2 up with two holes left when the round was to resume Friday morning.
At least Thorbjorsen reached the second round.
Mark Goetz, the medalist in qualifying to become the No. 1 seed for match play, grew up some 40 miles away and had plenty to cheer when he was 3 up with four holes to play.
David Nyfgall of Sweden then flipped the match by winning the next four holes — his only birdie was on No. 18 — for a 1-up victory.
Nyfgall only qualified by winning a 12-way playoff for the final spot in match play. Nyfgall was tied through 20 holes with Florida star Ricky Castillo when play was stopped.
Eddie Lai took down second-seeded Brian Ma, 4 and 2. Travis Vick, the No. 4 seed, beat Preston Summerhays, 4 and2.
The plan was to resume the second round Friday. The original schedule was for the second and third rounds to be played Thursday, with the quarterfinals Friday.