WIMBLEDON, England(AP) Teenage qualifier Melanie Oudin (Oo-dan') of Marietta, Ga., has advanced to the fourth round in her first Wimbledon by upsetting former No. 1 Jelena Jankovic, 6-7 (8), 7-5, 6-2.

The No. 6-seeded Jankovic struggled with the heat on a sunny, 82-degree Saturday. When the 66-minute first set ended, 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. Play resumed after a 12-minute delay, and Oudin was the steadier player from the baseline the rest of the way.

The 17-year-old Oudin had an 0-2 record in Grand Slam matches before making her Wimbledon debut this week.