The sudden emergence of 18-year-old Canadian Bianca Andreescu on the tennis circuit is surprising experts and family members alike.

The 152nd-ranked Andreescu completed back-to-back upsets of women’s tennis greats Caroline Wozniacki and Venus Williams this week, to reach the semifinal of the ASB Classic in New Zealand.

“I’m still in shock to be honest,” Nicu Andreescu, Bianca’s father, told CTV News Channel. “It’s been an unbelievable few nights. I’ve been watching her and I could barely get some sleep.”

On top of facing some of the best players in professional tennis, Nicu says his daughter has also been battling the extreme heat in New Zealand and some adrenaline-fueled sleep deprivation.

“The last two nights she went to bed at two o’clock in the morning there,” he said. “She tries to cope with the winning feeling and sometimes you can’t go to sleep.”

The Mississauga, Ont. native’s sudden ascension in the tennis ranks has vaulted her into a list of young up-and-coming Canadian tennis stars that includes Dennis Shapovalov and Felix Auger-Aliassime on the men’s side.

“It’s absolutely unbelievable,” said Mike McIntyre, writer with Ontario Tennis Magazine. “She has certainly announced her arrival to the tennis world.”

Shapovalov, 19, exploded onto the tennis scene in 2017, and has since climbed into the ranks of the top 30 players in the world.

Auger-Aliassime, the 2016 junior U.S. Open champion, qualified for his first Grand Slam draw in 2018, but was forced to retire in the first round with heart palpitations. He currently sits 108th in the world rankings.

McIntyre said the trio of teenagers have made things exciting for Canadian tennis fans and could have a lasting impact on future generations.

“It’s going to put more tennis racquets in kids’ hands here in Canada, which at the end of the day is what Tennis Canada would love to see,” he said.

Nicu fondly remembers the days when his daughter was just one of the kids with dream of playing pro tennis. He says Bianca developed a routine early on – training two to three hours daily. As a teenager she decided to take school online so she would have more time to focus on tennis.

“She didn’t have a teenage school life like everyone is having,” he said. “It’s been challenging for her doing homework on the road.”

Andreescu will now face Su-Wei Hsieh of Taiwan in the semis, which are scheduled to be played around 12 a.m. EST on Saturday.

McIntyre says Hsieh provides a much different test than her previous opponents this week.

“It’s not someone who’s hard-hitting so much as Venus Williams, but someone who employs a lot more variety in her game,” he said. “Bianca’s going to totally have to adjust… and realize she’s going to be in for a much different battle.”