In 2015, Anastasija Sevastova came out of retirement. A year later, she scored the biggest win of her career – and one of the biggest upsets of 2016 – over No.3 seed Garbiñe Muguruza at the US Open.

Sevastova was a rising star back in 2011, reaching a career-high ranking of No.36 at 20 years old. But injuries soon sapped the desire away from the young Latvian, who hung up her racquets two years later, and was off the tour for two years more. After a few stints in coaching and studying, she decided to give tennis another go.

What brought her back to the sport?

“This one, this stage,” she said, gesturing to the enormous Arthur Ashe Stadium after her second round stunner. “I mean, look at that. It cannot get bigger.”

It doesn’t get much bigger than Arthur Ashe, and they don’t get much bigger than French Open champion Muguruza.

Sevastova, who started out the year ranked No.110, played well above her ranking and took a tight opening set at 7-5 before racing out to a 5-1 lead in the second.

With the finish line in sight, she faced a bit of a mental wobble as Muguruza clawed her way back up to 5-4 with the Spaniard serving to even the score.

In 2015, she came out of retirement. Tonight, she beats a GS champ. #Sevastova d. #Muguruza 7-5, 6-4. @MBUSA #usopen https://t.co/a5xfmjm8XC

— US Open Tennis (@usopen) September 1, 2016

“I stopped thinking. I was thinking too much at 5-2, 5-3. Then I said, ‘Okay, I have one more chance at 5-4. She’s serving. I broke her before enough times, so I will try this one more time,'” Sevastova explained.

“And still, even then it’s only 5-5. It’s still an open match like the first set.”

That positivity took the Latvian over the finish line, breaking serve to love to clinch the biggest upset of the US Open thus far – and the biggest win of her career – winning 7-5, 6-4.

But after the match, Sevastova was the first to keep her feet firmly on the ground.

“It still hasn’t settled in,” she said in her post-match press conference. “I mean, I’m tired mentally and it’s late. Normally I go to sleep at this time.

“It feels great, but it’s still not like I won the tournament. It’s only second round.” 

Sevastova would go on to reach her first Grand Slam quarterfinal – knocking out No.14 Johanna Konta along the way – but her colossal second round victory over the reigning Roland Garros champion clocks in as the No.5 biggest upset of 2016.

All photos courtesy of Getty Images.