After waiting out a delay caused by an ill spectator, 19-year-old Jack Sock of Lincoln, Neb., served out a 6-2, 6-2, 6-4 victory over 88th-ranked Flavio Cipolla of Italy on Thursday in the second round of the U.S. Open.
The 248th-ranked Sock, a wild-card entry, got to the third round at a Grand Slam tournament in singles for the first time. Next up is a meeting with No. 11 Nicolas Almagro of Spain, a 6-3, 5-7, 5-7, 6-4, 6-4 winner against Philipp Petzschner.
Sock teamed with Melanie Oudin of the U.S. to win the mixed doubles title at Flushing Meadows a year ago.