( CNN ) -- Maria Sharapova powered into the semifinals of the WTA tournament in Birmingham with a straight sets victory over old adversary Sesil Karatantcheva on Friday . Sharapova , who is bidding to win her second Wimbledon title , has had to play catch-up at the rain-hit warm-up tournament , which she has won twice . The second seed beat Bethanie Mattek-Sands of the United States and then fellow Russian Alla Kudryavtseva in straight sets on Thursday and gave Karatantcheva similar short shrift in a 6-2 6-4 victory . The two have history dating back to an on-court incident in 2004 at Indian Wells and Sharapova has easily won their two subsequent matches . Karatantcheva , the 2004 French Open junior champion , was only 16 when banned for two years in 2006 for a doping offence which she vigorously denied . Sharapova is seeded to meet China 's Li Na , who beat Kaia Kanepi of Estonia 6-4 6-2 , in the final on Sunday . Li will play Aravane Rezai of France , who dispatched Sara Errani of Italy 7-6 7-5 . Next up for Sharapova on the grass of the Edgbaston Priory club will be American teenager Alison Riske , who shocked Belgian third seed Yanina Wickmayer 6-7 6-4 6-3 on Friday . Riske had to come through qualifying and survived the loss of the first set on a tiebreak to take charge .
Maria Sharapova reaches last four of WTA tournament in Birmingham . Russian star sees off Sesil Karatantcheva of Kazakhstan in straight sets . She next faces Alison Riske of the USA who shocked third seed Yanina Wickmayer .