Tennis legend Martina Navratilova got engaged at the U.S. Open on Saturday, proposing to girlfriend Julia Lemigova in the middle of the two men’s semifinal matche. The winner of 18 Grand Slam singles titles, including four US Open championships, and her new fiancée drew cheers as the proposal was broadcast on the big screen at Arthur Ashe Stadium. “I was very nervous,” Navratilova said. “It was kind of an out-of-body experience. You’ve seen people propose at sporting events before, in movies, in real life. Here it was happening to me. It was like I was watching myself do it.” Navratilova’s engagement wasn’t the only surprise at Flushing Meadows on Saturday. Both men’s semi-finals ended in major upsets: Kei Nishikoir defeated top seed Novak Djokovic, and 14th-seeded Marin Cilic knocked out Roger Federer.