ACAPULCO, Mexico -- 17-year-old Canadian qualifier Leylah Fernandez extended her breakthrough WTA tournament on Thursday night, knocking out 18-year-old Anastasia Potapova of Russia, 6-3, 7-5, to notch her first-ever WTA semifinal at the Abierto Mexicano Telcel presentado por HSBC.

"There’s no words, honestly," Fernandez said, after her victory. "I’m full of emotions, I’m happy, excited. I’m just proud of myself and the way that I fought today."

"It wasn’t easy, Anastasia is a great player," Fernandez continued. "I knew that today was going to be a great battle, and it was. I’m so happy that I was able to come through in the end."

Read more: WTA Scouting Report: Leylah Fernandez dances up the rankings

In the first meeting between the teenagers, World No.190 Fernandez eliminated Potapova after 93 minutes of play. The Canadian, who won two matches in qualifying before her three-match streak in the main draw, won over three-quarters of points on her first serve, leading to four breaks of 97th-ranked Potapova in the affair.

The Canadian teenager had already gone farther than she ever had in a WTA tournament, upsetting No.8 seed Nao Hibino in the second round to reach her first WTA quarterfinal. Fernandez has now notched a number of milestones this season already: she also qualified for her first Grand Slam main draw at the Australian Open, and got her first Top 5 win over Belinda Bencic at Fed Cup. 

Fernandez will meet another first-time WTA semifinalist on Friday when she faces homeland heroine Renata Zarazua. World No.270 Zarazua, a 22-year-old wildcard, thrilled the Acapulco crowds with a three-set victory over Tamara Zidansek of Slovenia earlier on Thursday, becoming the first Mexican semifinalist on the WTA since 1993.

"It’s going to be a battle," said Fernandez. "[Zarazua is] a great player, she’s here playing at home, I know that feeling. I’m just going to try to focus on me, stay positive, and go for my shots."

Potapova picked up the early lead in the encounter, forcing an error with her forehand to break Fernandez in the opening game, then consolidating for a 2-0 advantage. However, after Potapova missed a game point to take a 3-1 lead, Fernandez started to fight back, punching a volley winner to level the set at 2-2.

Fernandez saved a break point with a winning backhand en route to a hold for 3-2, then used a crosscourt winner from that side to convert a break point in the next game and move ahead by a service break. The Canadian ramped up her winning streak to five straight games as she suddenly had opened up a 5-2 lead.

Serving for the set at 5-3, Fernandez squandered one set point, but on her second chance, the Canadian teen fired a strong serve to draw a netted return from Potapova, wrapping up the opening frame. 

Fernandez clinched the early lead in the second set as well, emerging triumphant at 1-1 by converting her fourth break point of that game, after a netted backhand by Potapova, to seal a 2-1 lead.

The Russian, though, was not done yet, and at 4-3, she queued up a break point with a crosscourt backhand passing winner, and converted the break after a long backhand by Fernandez.

But at 5-5, 30-30, Fernandez ended a grueling rally with a scintillating down-the-line passing shot, earning a key break point, which she converted. Serving for the match at 6-5, Fernandez let three match points slip and faced a late break point, but she erased Potapova’s last chance with a forehand winner, then claimed victory on her fourth match point.

Fernandez said the key to closing out the tight second set was "just trying to keep my emotions in check. I was getting a little bit excited to finish the match, and she was doing great shots, getting back some great defensive balls. So it was just to stay calm and focus on my game instead of hers."

2020 Acapulco Highlights: Canadian teen Fernandez surges into first QF