OAKMONT — Michael Thorbjornsen made five straight birdies to win his first match and needed another big comeback in the second round of a U.S. Amateur that faced more delays Thursday.

Only four of the 16 second-round matches at Oakmont finished before play was suspended for the second time because of storms in the area. The first delay was for just under an hour.

There already have been four weather delays of a combined 10 hours this week. A two-tee start was used for the second round, and that was the plan for the third round.

Thorbjornsen, a former U.S. Junior Amateur winner, was 3 down with six holes to play against William Hott when the Stanford sophomore ran off five birdies in a row.

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.

The plan was to resume the second round Friday.