US teen giant-killer Melanie Oudin continued her astonishing US Open run on Monday, the 70th-ranked blonde pixie ousting 13th seed Nadia Petrova 1-6, 7-6 (7/2), 6-3 to reach the quarter-finals. The tenacious pint-sized American dynamo, who turns 18 on Septmeber 23, has become the darling of the Flushing Meadows fortnight. Oudin, a comeback queen, improving to 9-2 this year when losing the first set, and 17-4 in all three-setters, with her third comeback victory in a row to eliminate a fourth consecutive Russian rival. 'I didn't think I started off too well and Nadia served unbelievable, but I stayed in there with her in the second set and she gave me a few free points and I got my confidence and I believed I could do it and I did it,' Oudin said. The magic act by 'Oudini' has made her the youngest American in the US Open's last 16 since Serena Williams a decade ago, showing her Wimbledon ouster of former number one Jelena Jankovic was no fluke. 'It was tough. She was all over me. I kept fighting and I got that break and I'm so happy that I won,' said Oudin, her voice breaking with joy. 'I'm so glad to be in my first Grand Slam quarter-final ever.' Oudin will play for a semi-final spot against the winner of a night match between Danish ninth seed Caroline Wozniacki and Russian sixth seed Svetlana Kuznetsova. Reigning French Open champion Kuznetsova is the only player to beat second seed Serena Williams at a Grand Slam event this year, ousting the Australian Open and Wimbledon winner in the quarter-finals. While Oudin cannot speak French despite her Gallic surname, she has shown a mastery of Russian, rallying from first-set losses to dump fourth seed Elena Dementieva and former world number one Maria Sharapova on the scrap heap. Oudin seized a 5-0 lead in the tie-break and traded points from there to claim the second set when Petrova sent a forehand wide. Petrova rescued six match points in the opening game of the last set but was broken on Oudin's seventh chance by a lob dropped just on the backline. Petrova broke back to 2-2 but surrendered a break in the next game with a double fault to put the home-crowd heroine back on top and Oudin held at love for a 4-2 edge. Oudin reached 15-40 in the seventh game and Petrova handed over a break when she fired a forehand smash long, her 58th of 59 unforced errors in the match. Oudin was broken when serving for the match but won the first three points off Petrova's serve in the next game. Oudin sent a forehand long and backhand wide but her forehand winner finally ended it after two hours 27 minutes. Ranked 221st a year ago, Oudin wears the word 'believe' on her yellow and pink shoes at her boyfriend's suggestion. She made a believer of Petrova despite a rough start. Petrova broke Oudin's first three service games while giving up only one of her own to claim the first set in 31 minutes. Oudin broke for a 3-1 lead in the second set but Petrova answered with a break, held at love, and broke again for the lead. Oudin broke back in the eighth and they held serve from there into the tie-break. In another fourth-round match, Ukraine's 52nd-ranked Kateryna Bondarenko, blanked Argentina's Gisela Dulko 6-0, 6-0 in 47 minutes to avenge the South American's second-round ouster of her older sister Alona. 'She kissed me I think five times,' Kateryna said of Alona. 'I think she is very happy.' Bondarenko, who saved a match point in her opener against Serbian 11th seed Ana Ivanovic, took revenge for Dulko's 6-4, 6-0 victory over her sibling. 'Maybe a little bit,' Bondarenko said. 'I didn't think about it that way. I got some messages to do some revenge for my sister and I started to think about it when I got them.' Bondarenko will play for a semi-final berth against 50th-rated Yanina Wickmayer, a 19-year-old Belgian she beat in last year's Birmingham final for her only WTA title. Wickmayer advanced 4-6, 6-4, 7-5 over 72nd-ranked Czech teen Petra Kvitova, who ousted Russia's top-ranked Dinara Safina in the third round. 