Simona Halep and Garbiñe Muguruza, a pair of two-time Grand Slam champions who have had their difficulties in New York, pulled out tough two-set victories on Monday in the opening round of the U.S. Open.

Simona Halep and Garbiñe Muguruza, a pair of two-time Grand Slam champions who have had their difficulties in New York, pulled out tough two-set victories on Monday in the opening round of the U.S. Open.