Serena Williams beat Maria Sharapova for the 18th time in a row to reach the Australian Open semi-finals. The American defending champion, seeded number one and chasing a 22nd Grand Slam title, saw off fifth seed Sharapova 6-4 6-1 at Melbourne Park. It is 12 years since Williams lost to the Russian, and the world number one moves on to face fourth seed Agnieszka Radwanska in the last four. In the men’s draw, Roger Federer beat Tomas Berdych 7-6 (7-4) 6-2 6-4. The Swiss 17-time Grand Slam champion will play top seed Novak Djokovic or seventh seed Kei Nishikori in the semi-finals on Thursday.