Two-time defending champion Maria Sharapova needed eight match points to put away top-seeded Agnieszka Radwanska 6-4, 6-3 Friday for a place in the Porsche Grand Prix semifinals. Her semifinal opponent will be eight-seeded Sara Errani, who was leading 6-3, 6-7 (6), 3-0 when Carla Suarez Navarro retired with a hand injury. ''This was a big victory for me, the biggest since my injury,'' said Sharapova, who returned late last year after missing more than four months following shoulder surgery. Radwanska played her best tennis in the penultimate game, when she fought off six match points and finally broke Sharapova's serve. More...