Canadian tennis player Bianca Andreescu stunned the sports world again by defeating the legendary Venus Williams to reach her first WTA semifinal.

Andreescu, from Mississauga, Ont., won 6-7(1), 6-1, 6-3 over Williams at the ASB Classic in Auckland, New Zealand.

"I believe that anything is possible, and I think tonight I did the impossible," she said on the court following her win over the former world No. 1 player. "I don't even know what to say."

WATCH | Father, coach on Bianca Andreescu reaching 1st WTA semifinal:

18-year-old Canadian Bianca Andreescu defeated Venus Williams to advance to her first WTA semifinal. 3:19

After being broken in the opening game of the second set, Andreescu reeled off 11 straight games to take control of the match.

"I was like 'What is going on. I just broke her five times in a row,"' Andreescu said. "She's one of the best servers in the game. Today she didn't serve as well as other matches I've seen her play. But I took control of that. It was honestly a gift, maybe like a late Christmas present."

Andreescu admitted she was nervous after allowing Williams back to 5-3 in the third and final set.

"I got really tight at 5-0," Andreescu said. "I'm like 'I'm one game away from winning this' but then she started raising her level and I kind of stepped back. At 5-3, I'm like 'OK screw this. I'm just going to go for everything' and that's what I did and it worked. Maybe I should just do that every point."

WATCH | Andreescu's victory over Venus Williams:

The 18-year-old will play in her first career WTA semifinal after beating Venus Williams in New Zealand. 1:13

Key decisions

After recovering from a back injury last summer, Andreescu looked to build her strength and confidence by competing in the lower-level Challenger series. She also moved her off-season training location from Boca Raton to the IMG Academy in Bradenton, Fla., which allowed her to practise against tougher opponents.

Those decisions helped Andreescu quickly return to form and start this season feeling strong and assured. Her most recent upsets against former world No. 1s Caroline Wozniacki and Venus Williams in the ASB Classic can attest to that.

"She showed up in Auckland full of confidence and playing really, really well," said Canadian women's head coach Sylvain Bruneau. "To be honest, I knew. We've been talking and texting. I knew that she was going to get into the main draw and play the top players. I believe in her game a lot.

"It was a matter of her believing that she could just go out there, play her game, lay it out on the court and just believe."

Exceeding expectations

The 18-year-old is riding high just a day after the biggest win of her career, a stunning 6-4, 6-4 victory on Thursday over world No. 3 Caroline Wozniacki in the $250,000 US Auckland tournament, which is considered a warm-up for the Australian Open that begins in just over a week.

"It feels like a double dream," Andreescu said. "I'm really just speechless. I don't know if this is a dream, if one of you can pinch me please. Honestly, I've worked really hard for this moment. I'm just really grateful."

"I've pictured myself beating top players like this, and it's really just a dream come true," Andreescu said after defeating Wozniacki. "I know I have the level. [My confidence] skyrocketed like 20 times today. She was No. 1 in the world and won a Grand Slam. I just fought until the end. I was in the zone and at one point, I didn't even know the score.

"My goal was only to qualify and maybe get a couple of rounds in, but now I beat a couple of top players so who knows? I believed in myself to the end," said Andreescu, who is ranked 152nd in the world and had to go through qualifying to make the tournament. "I fought and I really enjoyed myself."

Andreescu will hope to land one of 16 qualifier spots in the 128-player main draw at the first Grand Slam of the season because her ranking is not high enough for direct entry.

"She's only 18 and she's got really, really good potential," Bruneau said Friday from Melbourne. "From an athletic perspective and also from a competitive standpoint mentally, [she's] a great athlete. It's all very exciting. There's a lot more tennis to [play] and a lot more improvement, [we'll] keep working.

"For sure that first tournament of 2019 is very positive and reinforces the stuff that we've been doing."

Those thoughts were echoed by Andreescu's frequent doubles partner Carson Branstine.

"She can do any shot you can ask of her," Branstine said from Orange County, Calif. "I really think that it might throw a lot of girls off because they're not used to a girl like Bianca playing. There's a lot of women that kind of just play one way, where Bianca can play any game style that she needs in order to win matches.

"I think that's going to really benefit her in the future because there aren't very many people who can actually do it like she does."

WATCH | Andreescu inspiring young Canadian tennis players:

Mississauga, Ont., native Bianca Andreescu defeated Australian Open champion Caroline Wozniacki on Thursday. 2:14

​Andreescu will now take on the tournament's No. 3 seed Su-Wei Hsieh of Taiwan Saturday morning at no earlier than 12:15 a.m. ET.

Andreescu said she avoided social media after the Wozniacki match, but admitted that she might take a peek following the triumph over Williams.

"You have to start somewhere and I guess this is my awakening moment, maybe," she said. "I'm just really happy and hopefully I continue like this for the rest of the season, for the rest of my career."

Andreescu's surprise performance has moved her to the front of sports pages across the country and generated plenty of buzz on social media. Bruneau said Andreescu is prepared for the heightened attention.

She will top her career-high ranking of No. 143 (set Aug. 14, 2017) when the new list is released next week, WTA Tour statistics and information director Kevin Fischer said in an email.

It's too early for specifics since other results may factor in, but she's projected to move to No. 114 by reaching the semifinal. A win on Saturday could bump her up to No. 107 and a victory in Sunday's final could launch her as high as No. 89.

"You just need to be really grounded," Bruneau said. "We know she's ranked around 150. She's going to go up in the ranking with this but we're still very far from where I think she could be.

"So it's all about keep working, progressing, stay in the moment and do the right thing."