Pegula foils Ruse to reach US Open second round

The U.S. Open's Sunday start allows some players a head start, such as Novak Djokovic. The 24-time Grand Slam champion suffered a first-round loss, beaten by Mariano Navone of Argentina in a grueling five-set match. Djokovic, 39 years old, battled leg issues during the grueling match that lasted over 4 1/2 hours. Venus Williams and Sofia Kenin faced a late start, only playing after midnight.

Three-seeded Jessica Pegula capitalized on the Sunday start, winning her match easily and will face Kenin in the second round. The No. 11-seeded Kostyuk also had a strong start to the year's final major, beating Storm Hunter 6-4, 6-1. Some top contenders, including two-time defending champion Aryna Sabalenka and last year's champion Carlos Alcaraz, begin their matches on Monday. Seven matches were rained out, causing delays.