Some tennis players celebrate huge wins with drinks or dessert.

Mika Stojsavljevic had something much grander in mind: A delicious meal from Chipotle.

“I love American food,” the 15-year-old said Wednesday. “Chipotle and Crumbl cookies are my favourite.”

Whether Stojsavljevic went for a chicken quesadilla, a burrito bowl or a taco is unknown, but there are many Chipotle establishments in New York City.

But whatever she ate, she absolutely deserved it. The six-foot precocious talent from London smacked 13 aces on Court 12 and shocked No. 1 seed Emerson Jones 7-5, 6-4, in the third round at the US Open Junior Championships, and in so doing advanced to her first-ever Grand Slam junior quarter-final.

Stojsavljevic will have the rare occurrence of playing someone younger than her on Thursday in the quarters, facing 14-year-old unseeded American Annika Penickova.

“That was amazing,” she said moments after the win. “Can’t imagine anything better.”

LTA head boys coach Martin Westin had three things to say to his player before the final game on Wednesday: As Stojsavljecic walked to the line to try to serve out the biggest win of her career, Westin calmly said “Don’t think about the score, move your feet, and take your time between points.”

“I heard him; it’s hard not to hear him because Martin is quite loud,” Stojsavljevic said with a laugh. “But I love it. I like to listen to my coaches and let them help me. I knew I had to stick to my guns in that game, and if I gave her a look she would pounce.”

Stojsavljevic, who turns 16 in December, reached the second round at Wimbledon this year, third round in Australia, and the final of a J200 in Thailand in February.  

But it was her success winning a women’s W35 event on the ITF World Tennis Tour in Nottingham in April that gave her a ton of confidence.

“Definitely showed me my level is there,” Stojsavljevic said. “I’m still working on getting consistency, but that gave me a huge boost.”

Women’s LTA coach Katie O’Brien said Stojsavljevic has just begun to tap in to her talent.

“She’s got some huge weapons, and is developing as a person and as a competitor every day,” O’Brien said. “Her hard work is coming to fruition this week. She’s building her confidence and can take the game out of a lot of players’ hands when she’s feeling good.”

Stojsavljevic has trained for the past two years at Loughborough University National Tennis Academy, and got her start in tennis almost by accident.

She said when she was five years old, her brother Sava was taking a tennis lesson and she was just there watching. Sava decided he didn’t want to play anymore, so Mika’s parents said she should take the lesson instead.

“He put the racket down, and I picked it up, and have been playing ever since,” Stojsavljevic said.

Now she gets to spend some more time in New York, which she called “her second favorite city besides London".

Last year a trip here meant visiting Ground Zero, which “was very touching. Very, very sad but very important to see.”

Now, she’s halfway to a Slam and starting to believe.

"I felt like I was ready to win some matches at the biggest stage,” she said. “Having that experience of having tough matches this year has helped so much.”