Leylah Fernandez has claimed the biggest title of her career…

The 22-year-old half-Ecuadorian Canadian tennis player won the DC Open on Sunday with the help of a terrific backhand, some superb returning and energy courtesy of Shake Shack‘s burgers and fries.

The left-handed Fernandez, who is ranked 36th, wrapped up a big week of tight matches with a lopsided victory, defeating Anna Kalinskaya 6-1, 6-2 in the final.

Fernandez earned her fourth singles trophy — all have come at hard-court tournaments — and first at a WTA 500 event.

She came quite close to a Grand Slam championship as a teenager at the 2021 US Open, making it all the way to the final in New York before losing to Emma Raducanu.

There almost was a rematch in Washington, but Kalinskaya eliminated Raducanu in the semifinals Saturday.

Fernandez took quite a journey through the women’s bracket.

She needed 2 hours, 19 minutes to oust No. 1 seed Jessica Pegula, last year’s US Open runner-up, in three sets in the second round. She then needed 2 hours, 20 minutes to beat Taylor Townsend in the quarterfinals and 3 hours, 12 minutes for a three-tiebreaker victory over No. 3 seed Elena Rybakina, the 2022 Wimbledon champion, in the semifinals.

After each of the last two, Fernandez and her father, who is also her coach, opted for Shake Shack.

“We got burgers, hot dog, cheese fries — everything that an athlete should not eat before a match, but it did the trick,” Fernandez said about what she ate after the Townsend match. “It gave me the right nutrients to recover from the cramps and get ready for the next round.”

Following the Rybakina marathon, Fernandez said she and her father “were messaging, and I was, like, ‘OK, what do you want to eat tonight?’ We both answered at the same time: burgers. … That was kind of my diet for the whole week.”

It worked: This was the first title for Fernandez since October 2023 at the Hong Kong Open.

Plus, she arrived in Washington with a losing record this season and hadn’t won more than two matches at the same tournament since last November.

“I have gone through so many different challenges this week. It just has made me stronger, in a way, that if I can get through this week — through the cramps, through the long matches, through the heat, the humidity — I can get through anything,” Fernandez said. “So I was just very happy that I got to not only push myself physically through the limits, but also mentally. So that kind of will help me hopefully for future tournaments.”

Against the 48th-ranked Kalinskaya, who hadn’t dropped a set until Sunday, Fernandez saved the only break point she faced while breaking four times.

One key: Fernandez claimed 10 of the 12 points when Kalinskaya hit a second serve. Another: Kalinskaya, a 26-year-old Russian who is 0-3 in tour finals, finished with 24 unforced errors and just nine winners.

“Amazing fight this week,” Kalinskaya told Fernandez. “You truly deserve it.”