NEW YORK, Sept 8 (Reuters) - No one is more surprised than Emma Raducanu herself. The British teenager became the first qualifier to reach the U.S. Open semi-finals by beating Olympic champion Belinda Bencic in straight sets on Wednesday. "I didn"t expect to be here at all," Raducanu told reporters. "I think my flights were booked at the end of qualifying, so it"s a nice problem to have." The upbeat and smiling 18-year-old has made short work of her U.S. Open campaign, winning all 16 sets she has played from qualifying through to the semi-finals, proving lethal at the net and from the baseline. Raducanu is continuing her remarkable journey through the tournament without her parents in the stands, telling reporters they would need a waiver - which takes a couple weeks - in order to travel. Their influence is still felt even from afar, however, as she maintains an on-court composure far beyond her years on the biggest stage. "The calmness and the mental strength definitely comes from my upbringing," Raducanu said. "My parents have both instilled in me from a very young age to definitely have a positive attitude on court, because, yeah, when I was younger, it was definitely an absolute no-go if I had any sort of bad attitude." Drawing comparisons with Swiss Martina Hingis, the youngest player to win a Grand Slam title, Raducanu made the fourth round of her Wimbledon debut this year to announce herself as another potential star of British tennis. "We have some great role models to look up to," said Raducanu, who won her quarter-final against American Shelby Rogers with Virginia Wade, the last British woman to win Wimbledon, in 1977, watching on from the stands. "Andy (Murray) has quite often spoken to me, and I actually hit with him two times, which was really good for me to see his ball speed and how good he is... all are such great role models and figures for me to follow," Raducanu said of her compatriot Murray, a three-times Grand Slam singles champion.