Iga Swiatek Loses on Her Birthday to Marta Kostyuk, Updated Women's Bracket at Roland-Garros 2026

Iga Świątek's 25th birthday is one she'll quickly try to forget.

The six-time major champion was upset by 15th-seeded Marta Kostyuk in straight sets, 5-7, 1-6, in the fourth round at Roland-Garros.

The result guarantees there will be a first-time champion in Paris in the women's singles draw. Kostyuk and Sorana Cirstea are the first two through to the quarterfinals so far.

"To beat such an unbelievable player who won four times here, I'd lost [three] times to her, never taken a set off her, I still cannot believe it," Kostyuk said, per ESPN.com. "I think the most important thing I've been doing is really just trying to enjoy. I woke up this morning and I just thought about what an unbelievable day I have to live today to play on Chatrier against Iga."

She awaits the winner of No. 7 Elina Svitolina vs. No. 11 Belinda Bencic, and despite what is still a tricky road ahead, she might be the favorite at this point.

The 23-year-old has dropped just one set through her first four matches at Roland-Garros. She entered the tournament on the heels of wins in the Open de Rouen and Madrid Open. The latter saw her knock off Jessica Pegula, Linda Noskova and Mirra Andreeva en route to the title.

After a tightly contested first set, it looked like Świątek was regaining control when she broke Kostyuk's serve in the opening game of the second. The four-time Roland-Garros winner couldn't maintain that momentum, though, as she immediately dropped serve. Then she failed to capitalize on three opportunities to earn another break in the third game.

Once Kostyuk held to take a 2-1 lead in the set, she didn't look back.

Świątek lacked her usual sharpness. She committed five double faults and had 39 unforced errors to 13 winners. Even the best can have a bad day at the office.

This matches her worst showing at Roland-Garros. She didn't make it out of the fourth round in 2019, her first appearance at the event.