OAKMONT — Nick Grabelcik played 38 holes to win three matches Friday, sending the North Florida sophomore into the semifinals of the U.S. Amateur at Oakmont.

Coming off a superb freshman year that included three wins and a spot in the Palmer Cup, Grabelcik is one match away from an exemption to the Masters and U.S. Open.

It wasn’t easy on a sweltering day that at least was free of storm delays and allowed the U.S. Amateur to get back on rack.

Grabelcik needed one hole to complete a 2-and-1 victory over former U.S. Junior Amateur champion Michael Thorbjornsen. He had to go 19 holes against Hugo Townsend of Sweden, beating him with a wedge that spun to 3 feet on No. 10 for birdie.

And then after leading the entire match, Grabelcik lost two straight holes and was tied with Davis Chatfield with four holes to play. Grabelcik hit 9-iron to 5 feet for a conceded birdie on the 15th and halved the last three holes — twice with bogey — for a 1-up victory.

That puts him in the semifinals against James Piot of Michigan State, who beat Matthew Sharpstene, 3 and 1.

The other semifinal match features Travis Vick, who is carrying the flag for the Texas Longhorns, against Austin Greaser.