Celebrities were out in force on Saturday night to watch history in the making when Venus Williams, 21, won the U.S. Open Women’s Singles Final by defeating her 19-year-old sister, Serena, 6-2, 6-4, in the first major championship match between sisters in more than a century. Hours before the match, reports PEOPLE, a galaxy of stars — including Katie Couric, Matthew Modine, Phillip Seymour Hoffman, Gretchen Mol, Mary Tyler Moore, Rosie Perez, Candice Bergen, Stanley Tucci, Jerry O’Connell, Taye Diggs, Boris Becker and John McEnroe — gathered at an casually elegant party hosted by the United States Tennis Association and USTA Chief Executive Arlen Kantarian in a tent just outside of Arthur Ashe Stadium. “I love them both!” said Hilary Swank, 27, who showed up with hubby Chad Lowe, 33. (Throughout the match they chatted with late arrival Sean "P. Diddy" Combs.) “They’re my favorite tennis players, so I feel I can’t be let down in any way.” Macaulay Culkin, who’s just turned 21, told PEOPLE that he was rooting for the elder Williams. “I’m a Venus person,” he said. “I’ve always been a fan. I watched her since she came out at 16. I was 16, too, so it was that kind of thing.” Going into the game, Linda Fiorentino had no idea how the Williams could play against each other. “I have five sisters and we’re not competitive at all,” said the “Men in Black” star, 41. “I’m an older sister to four younger sisters, and I would let them win, because my father would be really mad at me if I didn’t.” On Sunday, Australian Lleyton Hewitt, 20, defeated 30-year-old Pete Sampras, 7-6 (4), 6-1, 6-1. Paul McCartney and his fiance, Heather Mills, were among those who watched.