Czechs STILL bringing the drama at the U.S. Open, part 3: Muchova overcomes both injury and a fierce opponent

Half celebration, half relief.

Karolina Muchova triumphs in a grueling three-setter against Marta Kostyuk to reach the US Open quarter-final. pic.twitter.com/AVeeQAGiDr

— Jimmie48 Photography (@JJlovesTennis) September 1, 2025

Two of my favorite players to watch are Karolina Muchova and Marta Kostyuk--Muchova for her athleticism and artistry, Kostyuk for her athleticism and tenacity. The two met in the U.S. Open round of 16 today, and they didn't disappoint. And in Muchova's case, there was a very familiar feature I was hoping I wouldn't see.

After taking the first set 6-3, partway into the second set, Muchova took a medical time out, presumably for her lower back. The Czech player's career has been so hampered by injury that to see her have a physical problem on the court is nothing short of fear-inducing. Muchova returned to the court, but it was obvious that she was still in pain. However, the quality of the match was not compromised.

Midway through the second set, Muchova, not surprisingly, called for the physio again. She returned to the court to serve, but again, her movement was hampered. She reverted to guile (not a hard thing for her to do), which is needed against Kostyuk, even if everything else is going well. To add to the plot, the two had somehow never played each other before, so there was a bit of mystery about the whole affair.

The second set went to a tiebreak, which Kostyuk won 7-0. Given the Ukrainian player's momentum and her opponent's injury (and long history of injury-ridden back luck), one would think that the stage would have been set for Kostyuk to surge forward. However, perhaps guided (consciously or otherwise) by the Krejcikova Factor, Muchova went up 4-1, then 4-2, but then Kostyuk got break points, and the seventh, rather entertaining, game dragged on for some time. 

Muchova won it, and went up 5-2, after which a determined Kostyuk served a love game. With her opponent leading 40-0 in the next game, Kostyuk saved two match points, but it wasn't enough. After two hours and 53 minutes, the 11th seed got her victory. In the end, it came down not only to Muchova's ability to fight through her discomfort, but also to Kostyuk's failure to convert all but one of ten break opportunities.

Also winning today were 2nd seed and 2022 champion Iga Swiatek, who defeated Ekaterina Alexandrova 6-3, 6-1, and two-time champion Naomi Osaka, who upset 3rd seed and 2023 champion Coco Gauff 6-3, 6-2. This was Oaska's first time to go past the third round since her 2020 title run.

In the night match, 8th seed and Wimbledon finalist Amanda Anisimova faced off against 18th seed Beatriz Haddad Maia. And while the Brazilian player can wear an opponent down, she didn't get a chance to wear down Anisimova, who defeated her 6-0, 6-3.

Here is the quarterfinal draw:

Aryna Sabalenka (1) v. Marketa Vondrousova
Jessica Pegula (4) v. Barbora Krejcikova
Karolina Muchova (11) vs. Naomi Osaka (23)
Amanda Anisimova (8) v. Iga Swiatek (2)

In doubles, the five top seeds are into the third round. The only unseeded team left is that of Leylah Fernandez and Venus Williams, and they will face top seeds Katerina Siniakova and Taylor Townsend in the quarterfinals.