NEW YORK (AFP) - Powerhouse teen phenomenons Melanie Oudin and Caroline Wozniacki rallied Monday to complete an ouster of Russian stars from the US Open and advance to their first Grand Slam quarter-finals. The unseeded Oudin, who turns 18 on September 23, ousted 13th seed Nadia Petrova 1-6, 7-6 (7/2), 6-3. It was her third triumph in a row after losing the first set to a seeded 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. Danish ninth seed Wozniacki blasted sixth seed Svetlana Kuznetsova 2-6, 7-6 (7/5), 7-6 (7/3), never trailing in either tie-breaker and keeping the pressure upon the 2004 US Open champion all night. "She just played unbelievable the first set and I didn't know what to do," Wozniacki said. "I needed to step into the ball because she was dictating the game. My tactic was to put pressure on her, be the first one to dictate." The reigning French Open champion fired 59 winners but lost by making 63 unforced errors, 31 more than Wozniacki."It was my game and I lost it," Kuznetsova said. "I couldn't control my emotions. I wanted it so much. I was giving her some chances. I gave her the chance to come back, to believe should could win. "Give her credit. She put the balls back in the court but I was beating myself. I was making too many unforced errors. I was missing easy balls and I can't do that." The other quarter-final Wednesday will also feature Slam quarter-final debutantes as Ukraine's 52nd-ranked Kateryna Bondarenko, who beat Argentina's Gisela Dulko 6-0, 6-0, faces 50th-rated Yanina Wickmayer, a 19-year-old Belgian that Bondarenko beat for her only WTA title in last year's Birmingham final. But the focus will be upon Oudin and Wozniacki. While Oudin cannot speak French despite her Gallic surname, she has shown a mastery of Russian, rallying from first-set losses to eliminate fourth seed Elena Dementieva, former world number one Maria Sharapova and Petrova. "I know I can compete with the best in the world," Oudin said. "I'm staying in there the whole time. I'm not giving up. Even if I get a set down I believe in myself. I know if I fight as hard as I can that I can do it." Wozniacki knows she will face a hostile crowd at Arthur Ashe Stadium in support of the home-nation heroine. "She has had such a great run. She has played some amazing tennis," said Wozniacki. "It's going to be a tough match but I'm going to give it all I've got. Hopefully somebody will cheer for me." Comeback queen "Oudini" improved to 9-2 this year when losing the first set, and 17-4 in all three-setters, becoming the youngest American in the US Open's last 16 since Serena Williams a decade ago. Kuznetsova was the only player to beat US second seed Serena Williams at a Grand Slam event this year, ousting the Australian Open and Wimbledon winner in the quarter-finals.Kuznetsova took advantage of all three break chances to win the first set in 27 minutes, but blundered in the tie-breaks. Wozniacki served for the match at 5-3 but was broken, then Kuznetsova saved match points in the 10th and 12th games before again failing in the decider. "I felt like I was in control of almost all the points," Kuznetsova said. "It's just the tie-breaks I played bad." Oudin, ranked 221st a year ago, 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, dropping the first set in 31 minutes. Petrova led 4-3 when Oudin broke to equalize and they served to a tie-break, in which Oudin seized a 5-0 lead and won when Petrova sent a forehand wide. Petrova rescued six match points in the opening game of the last set but was broken by a defensive lob winner, opening the floodgates. Oudin won on her third match point when her forehand winner finally ended it. "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. Bondarenko, who saved a match point in her opener against Serbian 11th seed Ana Ivanovic, took revenge for 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." 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.