Today at U.S. Open: Rain Postpones Women's Semifinals Until Friday

Serena Williams of the U.S. returns a shot to compatriot Madison Keys during their fourth round match at the U.S. Open Championship in New York on September 6. Carlo Allegri/Reuters

Updated | On the 11th day of the U.S. Open, rain has postponed the women's semifinals, according to the United States Tennis Association (USTA). They will now be played starting Friday morning instead of Thursday.

Serena Williams, the No. 1 seed and winner of the last four major tournaments, will face off against Roberta Vinci of Italy at 11 a.m. on Friday. They previously were scheduled to compete Thursday at 7. The other semifinal, featuring No. 2 Simona Halep of Romania against Italy's Flavia Pennetta, the No. 26 seed, will follow. The winners of the two semifinals will play each other in the final on Saturday afternoon.

The men's semifinals will move from a start time of 3 p.m. to 5 p.m. ET on Friday. The matches will be Novak Djokovic vs. Marin Čilić, and Stan Wawrinka vs. Roger Federer. The winners will compete in the men's final on Sunday evening.

The final of each year's four Grand Slam tournaments, the U.S. Open is held in late August and early September at the USTA Billie Jean King National Tennis Center in Flushing Meadows, New York.

Fans can check the schedule for the latest scheduling updates.

This story has been updated to include scheduling changes at the U.S. Open.