NEW YORK (AP) — John Isner, a former top American college player, beat this year’s top American college player in the first round of the U.S. Open.

The 13th-seeded Isner defeated Marcos Giron 7-6 (5), 6-2, 7-6 (2) on Tuesday. Giron earned his first spot in a Grand Slam tournament when he won the NCAA title for UCLA in May.

The big-serving Isner didn’t face a break point. He has shown that a player can compete in college then succeed in the pros after a successful career at Georgia from 2004-07. He’s the only American man currently ranked in the top 40 in the world.

The 21-year-old Giron announced in July he was turning pro after his junior season.

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