Maria Sharapova's love affair with New York nights continued Saturday as the 2006 US Open champion swept past 10th-seeded Jelena Ostapenko and into the fourth round at Flushing Meadows. Sharapova is now undefeated in 22 night matches at the Billie Jean King National Tennis Center. "There's no doubt I feed off this energy," Sharapova said. "We all spend so much time on the back courts with our teams practicing. "When you get a chance to come out here why not give everything that you have."