NEW YORK -- Ninth seed Martina Hingis struggled early but then showed her class to power past Italian qualifier Antonella Serra Zanetti 6-4 6-1 on Thursday and progress to the third round of the U.S. Open.

Playing in only her second event since returning to the tour following ankle surgery, former champion Hingis was slow to warm up on a cool, breezy evening and quickly found herself down an early break and trailing the 120th-ranked Zanetti 3-1 in the opening set, Reuters reported.

Sergio Garcia watching from the stands, the Swiss former world number one twice broke serve to claim the first set.

Hingis, who won seven successive games on the way to a 5-0 lead in the second set, now meets South African Amanda Coetzer.