Surprise US Open finalist Leylah Hernandez said she is motivated by a teacher who told her to stop playing tennis and focus on school

• 19-year-old Leylah Fernandez said a teacher once told her to focus on school instead of tennis.
• Fernandez said she uses that teacher's word as motivation.
• Fernandez has had an unlikely journey but is now in the US Open final.

Like so many other professional athletes, Leylah Fernandez is fueled by those who doubted her.

The 19-year-old Canadian has stormed the U.S. Open, knocking off three top-10 opponents in the last four rounds to make the final.

According to The New York Times' Christopher Clarey, Fernandez is motivated by a teacher who told her she would "never make it" and to focus on school.

"Now I'm laughing," Fernandez said. "I'm just glad that she told me that because every day I have that phrase in my head saying that I'm going to keep going. I'm going to push through, and I'm going to prove to her everything that I've dreamed of, I'm going to achieve."

Fernandez has an unwavering swagger and belief in herself. She told reporters earlier in the tournament that she believes she is going to win every time she steps on the court.

"From a very young age, I knew I was able to beat anyone, anyone who is in front of me," Fernandez said, according to The Wall Street Journal's Joshua Robinson.

She added that that confidence extends to all matters.

"Even playing different sports, I was always that competitive, saying I'm going to win against them, I'm going to win against my dad in soccer, even though that's, like, impossible," Fernandez said, according to Robinson. "I've always had that belief."

That belief has been evident at the US Open, as she has dispatched Naomi Osaka, Angelique Kerber, Elina Svitolina, and Aryna Sabalenka, four players with physical advantages or more experience that could shake other opponents. Instead, Fernandez fought through nervy moments with cunning play, from well-placed serves to well-timed drop shots.

Fernandez has had an atypical background for most tennis players. She has largely worked with her dad, a former Ecuadorian soccer player, as her coach over going to prestigious academies. Her family faced financial hardships trying to keep up with her training schedule, and her mother had to move from Canada to California to take a job to support them.

Fernandez and her family eventually moved to Florida, where Fernendez could train year-round at a number of facilities, according to Robinson.

Now, a confident player with an unusual background has a chance to win one of the most unlikely US Open finals ever, facing off against 18-year-old Emma Raducanu of Britain. It's the first time two teenagers have met in a US Open final since 1999, when Serena Williams played Martina Hingis. At the time, however, both Williams and Hingis were top-10 players - Fernandez ranks 73rd and Raducanu ranks 150th.

With the way women's tennis has produced new champions - since 2015, there have been 13 first-time Grand Slams champions, according to Clarey - there's no guarantee that Fernandez will make it back to this stage. But she has surely made it further than her teacher believed.