NEW YORK (AFP) - Forgive Caroline Wozniacki that she hasn't had time for romance lately. She has been too busy playing the greatest tennis of her life and making an unlikely run into the US Open semi-finals. The Danish ninth seed, until now the highest-ranked player never to reach a Grand Slam quarter-final, advanced to the final four on the Flushing Meadows hardcourts Wednesday by defeating 70th-ranked US teen Melanie Oudin 6-2, 6-2. "I was really nervous, especially at the beginning and end of the match," Wozniacki said. "I'm just so happy that I fought so well and I managed to pull the match out." Becoming the first Danish man or woman in a Slam semi-final, surpassing the 1978 Australian Open quarter-final run of Dorte Ekner, has made Wozniacki a popular figure for romantic speculation back home. "I haven't read the newspapers in Denmark, but I'm sure they can find a boyfriend for me," Wozniak said. "I don't have any 'real' boyfriends right now. And usually I keep to one." It's no wonder she is unattached. Wozniacki has won 10 matches in a row after winning a tuneup title in New Haven the weekend before the start of the Open, where her run has sealed a jump to a career-best seventh in the rankings. "I feel great," she said. "I feel like I've played a lot of matches. I've been playing some great tennis. I'm really happy. I love to compete. Playing matches just makes it more fun and I don't really feel tired at all." While defending champion Serena Williams and Belgian comeback mom Kim Clijsters meet in Friday's feature semi-final, Wozniacki's match against fellow 19-year-old Yanina Wickmayer will send a player to Saturday's final as well. "I still actually cannot believe that I'm in the semi-finals, so it's going to be great to play that match," Wozniacki said. "I'm looking forward to that." Wozniacki's father Piotr played pro football in Poland and Denmark and her mother Anna played volleyball for the Polish national team. When it came to tennis, her idol was Swiss standout Martina Hingis. "She was thinking so well on the court. She knew where to place the balls," Wozniacki said. "She took advantage of the other girl's hard shots. I just liked the way that she knew every shot." Danish boxing star Mikkel Kessler suggested Wozniacki use boxing techniques to break up the tedium of training routines and the results have been good. "It's not only the boxing training," Wozniacki said. "You do at least 40 minutes on the treadmill and run a lot and strengthen your stomach, back, arms, shoulders - all the things you also need in tennis." Her mental game is also at a peak. "I'm thinking well on the court. I think that I make the right decisions," Wozniacki said. "I'm a fighter. I run well. But I'm also capable of changing the rhythm, being aggressive. I think I'm an all-around player."