The second day of the U.S. Open kicked off Tuesday with a victory for Andy Roddick but some high-profile upsets for women. Eighth-seed Caroline Wozniacki of Denmark was the highest seed to fall, losing to Romania’s Irina-Camelia Begu 6-2, 6-2. Christina McHale, seeded 21st, was the highest seeded American to fall, losing to Kiki Bertens of the Netherlands. Serena Williams defeated fellow American Coco Vandeweghe, while rising American star Sloane Stephens won an upset victory against Italy’s Francesca Schiavone. On the men’s side, Andy Roddick defeated his young American challenger, 21-year-old Rhyne Williams, while the defending champion, Novak Djokovic of Serbia, advanced easily.