Ivanovic overcomes battling Australian

Ana Ivanovic has marched into the fourth round at Wimbledon with a 7-5 6-2 win over Australia's Samantha Stosur. Breaking Stosur in the first game, the 13th seed Serb got off to a strong start but her opponent refused to go down without a fight. Stosur, a semi-finalist at Roland Garros earlier this month, broke back to level at 5-5 before she netted the ball to lose the first set. Ivanovic, seeking to add a Wimbledon crown to the French Open title she won last year, dominated in the second. She surged into a 4-0 lead before sealing victory on her second match point with a powerful serve.

She will play either the five-times champion Venus Williams or Spain's Carla Suarez Navarro for a place in the quarter-finals. Meanwhile the American teenager Melanie Oudin pulled off the biggest upset of the first week at Wimbledon on Saturday, beating former world No 1 Jelena Jankovic, 6-7 (8), 7-5, 6-2. The sixth-seeded Jankovic struggled with the heat on a sunny, 28C afternoon, and took a 12-minute break after the first set. The 2008 US Open runner-up also needed treatment on her left foot later, and she was plagued by erratic groundstrokes, while Oudin, 17, played with poise down the stretch and swept the final three games. Oudin arrived in London with an 0-2 record in grand slam matches, and she had to win three qualifying matches to make Wimbledon's main draw for the first time. She's ranked 124th and will crack the top 100 for the first time after the tournament. Playing on Court Three, she wore down Jankovic in an arduous first set. Oudin failed to convert four set points, committing an unforced error each time, but when the 66-minute set ended, it was Jankovic who appeared on the ropes. A trainer and doctor came on court to check Jankovic's pulse and blood pressure. She rested on a towel while being treated, and after several minutes sat up while ice was applied to her neck and midsection. Jankovic played on, but the match turned when Oudin overcame a 5-4 deficit in the second set. She repeatedly won points with drop-shots. The teenager smacked a forehand winner on the final point, then raised her arms in celebration. * With agencies