Serena, Djokovic in first-day action at U.S. Open

Open tennis championships on Monday's opening day of the year's final grand slam.

Australian Open and Wimbledon champion Djokovic closes the day program at Arthur Ashe Stadium against 89th-ranked Joao Souza of Brazil.

Three-times defending U.S. champion Williams, the Australian, French and Wimbledon champion seeking to become the fourth woman ever to complete a Grand Slam, opens the night program against 86th-ranked Vitalia Diatchenko of Russia.

The tournament's first match on the Arthur Ashe centre court pits seventh-seeded Ana Ivanovic of Serbia against Dominika Cibulkova of Slovakia, followed by two-times U.S. Open winner Venus Williams against Puerto Rican Monica Puig.

The second Opening Night match under the lights features two-times winner Rafa Nadal of Spain, the eighth seed, against up-and-coming Borna Coric of Croatia, an 18-year-old ranked 35th.

Ninth-seeded Marin Cilic of Croatia begins the defence of his men's title with a Louis Armstrong Stadium tilt against Guido Pella of Argentina.

Cilic follows Japan's Kei Nishikori onto the Armstrong court.

Fourth seed Nishikori, who fell to Cilic in the 2014 U.S. Open final, faces France's Benoit Paire in his opening match.

Russia's Maria Sharapova, the third seed, closes the Louis Armstrong day session against Australian Daria Gavrilova.