NEW YORK (AP) American Donald Young rallied to force a fifth set, then dominated a final tiebreaker to upset 14th-seeded Stanislas Wawrinka at the U.S. Open.

The 22-year-old Young won 7-6 (7), 3-6, 2-6, 6-3, 7-6 (1) in 4 hours, 20 minutes Friday. He matched his best performance at a Grand Slam by reaching the third round, which he also accomplished at Flushing Meadows in 2007.

Ranked 84th, Young got in on a wild card. In 2005, he became the youngest boy to finish a year as the top-ranked junior player, but has struggled to find the same success on tour. Young had to apologize to the U.S. Tennis Association in April after he posted an obscenity-laced message on Twitter criticizing the organization for not automatically giving him its wild card into the French Open.