(Flushing, NY) -- Top-seeded Serena Williams is moving on to the semifinals of the U.S. Open. She beat her sister, 23rd-seeded Venus Williams, in three sets on Tuesday at Arthur Ashe Stadium. Serena took the first set, 6-2, before dropping the second set, 6-1. Serena closed out the match in the deciding set by the score of 6-3. She is 3-and-2 against Venus at the U.S. Open. Serena Williams faces Roberta Vinci in the semis as she attempts to become the first woman to win a calendar-year Grand Slam since Steffi Graf in 1988.