Marta Kostyuk pulled off more than just a stunning upset at the Madrid Open—she celebrated her biggest career win with a back handspring that had the crowd on its feet. The 23-year-old Ukrainian defeated eighth-seeded Mirra Andreeva 6-3, 7-5 to capture her first WTA 1000 title, marking a major milestone in her promising career.

This victory wasn't just about the trophy; it was a testament to Kostyuk's rising momentum. After clinching a WTA 250 title in Rouen just a month earlier, she has now won two titles in four weeks. Her Madrid run will propel her to a career-high ranking of No. 15 in the world on Monday—a remarkable achievement for a player who has long shown flashes of brilliance.

But the celebration was anything but ordinary. After the final point, Kostyuk executed a flawless backwards handspring before posing for photos with the trophy alongside her two dogs. And then came the real surprise: a pair of "lucky" men's underwear that she credited with her success.

"We have a tournament laundry service, and sometimes the clothes get mixed up," Kostyuk explained with a laugh. "Last year we ended up with this piece of underwear that had 'Lucky Shorts' written on it. So we kept it." Her coach, Sandra Zaniewska, even drove to her father's house just to retrieve the lucky charm before traveling to Madrid. "We made this promise that if I'd win, we would bring the 'Lucky Shorts' for the photoshoot with the trophy."

For Kostyuk, the Madrid Open title carries deeper meaning. "This trophy tastes like champagne, no doubt about it," she said. "Watching this tournament as a child and remembering all the people who've won it before me, I never thought this was possible. It's amazing. It's one of the toughest tournaments of the year, and everyone plays so well, especially now. So it certainly tastes good, but I just want to enjoy this today and that's it."

For Andreeva, the loss was a bitter pill. The 17-year-old Russian prodigy, who had been riding high after reaching the final, struggled to hide her disappointment. "Every time I lose, it's like the end of the world to me," she admitted. "Sometimes I see other players smile right after the matches they lost. I don't understand how people do it. I wish I could do it. Every match that I lose is obviously very disappointing and very painful to me."

The match itself was a battle of contrasting styles. Kostyuk took the first set with a single break of serve, playing clean, aggressive tennis. The second set tightened dramatically, with both players trading breaks twice before Kostyuk found another gear, breaking decisively to seal the victory at 6-5.

For fans of women's tennis—and for anyone who loves a good underdog story—Kostyuk's Madrid triumph is a reminder that hard work, a bit of luck, and maybe even a pair of lucky shorts can take you all the way to the top.