Li Na reached the second round of the U.S. Open for the first time since 2009, beating Heather Watson in straight sets.

The ninth-seeded Li won 6-2, 6-3 on Monday. She's coming off a victory in Cincinnati, her first title since the 2011 French Open.

Li was upset as a top-10 seed in the first round at Flushing Meadows in each of the previous two years.

The 30-year-old from China had 28 winners Monday. The 71st-ranked Watson, the top-ranked British woman, took Maria Sharapova to three sets in the opening round in her first U.S. Open appearance last year.