Emma Navarro upsets Karolina Muchova to reach US Open fourth round

Emma Navarro ended Karolina Muchova's breakthrough season in the biggest upset of the 2026 US Open so far, beating the seventh-seeded Czech 6-3, 7-5 on Friday to reach the fourth round at Flushing Meadows. The American, seeded 26th, closed out both sets by winning the last three games, denying Muchova a run that had included a Wimbledon final and a maiden WTA 1000 title earlier this year.

The match on the Grandstand court turned on a handful of points in the closing stages of each set. Navarro converted 5 of 12 break-point chances and won 76 of 137 total points played, according to match statistics posted on the WTA's official tournament site. Muchova, who arrived with a career-best ranking of world No. 6, was serving to stay in the second set at 5-5 before Navarro broke and served out the match. It was the first career meeting between the two.

The numbers behind the upset

Both players held serve at a similar rate for most of the afternoon. Navarro hit three aces to Muchova's three, and the two converted break points at nearly identical clips — Navarro at 41.7 percent, Muchova at 37.5 percent. What separated them was composure late: Navarro saved 5 of 8 break points against her own serve, better than Muchova's 7 of 12, and finished with three double faults to Muchova's one. The loss marked Muchova's earliest exit from the US Open since 2022, a jarring result for a player who had entered the tournament as one of the form players in women's tennis.

For Navarro, it was her third win over a top-10 opponent since returning to full health this season, part of a run that has also produced a WTA title in Strasbourg in May and a first career grass-court final in Nottingham. It is her deepest run at Flushing Meadows since 2024, when she reached the semifinals at this tournament before losing to Aryna Sabalenka.

How both players got here

Navarro's path back to fourth-round contention was not a straight line. The 25-year-old, a former NCAA singles champion at the University of Virginia who reached a career-high ranking of world No. 8 in September 2024, saw her 2026 season disrupted by an extended health absence that forced her to withdraw from the Miami Open and skip her hometown event in Charleston. She did not return to the tour until May, and her form was shaky at first before she won the title in Strasbourg and reached the final in Nottingham on grass — results that steadied her ranking heading into the North American hard-court season and set up her current run in New York.

Muchova, 29, has followed close to the opposite arc. After years in which physical setbacks repeatedly interrupted promising stretches — including a muscular injury that hampered her during last year's US Open quarterfinal loss to Naomi Osaka — she put together arguably the best season of her career in 2026. She won her first WTA 1000 title in Doha in February, beating Victoria Mboko in the final for her first trophy of any kind since 2019, then reached the Wimbledon final in July, beating three Grand Slam champions along the way — Barbora Krejcikova, Naomi Osaka and Coco Gauff — before losing the title match. That run pushed her to a career-high ranking of No. 6. Earlier in this tournament, she and countryman Jakub Mensik had even won the mixed doubles title, beating Belinda Bencic and Flavio Cobolli in the final, a triumph that now stands in sharp contrast to her singles exit three rounds into the main draw.

Who is affected, and what it means for the draw

The result removes one of the tournament's most in-form players from the bottom half of the women's singles bracket and hands Navarro a favorable look at the second week. She next faces 21st-seeded Anna Kalinskaya, who beat Elina Svitolina to reach the round of 16 and against whom Navarro holds a 2-0 career head-to-head record, according to WTA tour statistics. A win would send Navarro to the quarterfinals for the second time in three years at the major that produced her best Grand Slam result to date. For Muchova, the loss ends her tournament well short of last year's quarterfinal showing at the same event, meaning she will shed ranking points on the WTA's official rankings when the list updates next week, even after a season that also included the Doha and Wimbledon runs.

Friday's schedule was an eventful one across the rest of the draw. Defending champion Sabalenka advanced in straight sets to set up a fourth-round meeting with American Taylor Townsend, and Wimbledon champion Linda Noskova came back from a set down to beat fellow American Ann Li and reach the same round. Jessica Pegula also moved through. The results leave a deep American contingent — long a storyline of this tournament — well represented heading into the second week:

• Emma Navarro (No. 26) advances to face Anna Kalinskaya (No. 21)
• Taylor Townsend advances to face defending champion Aryna Sabalenka (No. 1)
• Jessica Pegula advances to the round of 16
• Linda Noskova (No. 6) advances to a likely rematch with Marta Kostyuk

Reaction on court

Navarro was effusive in her on-court interview afterward, thanking the crowd on a court where she has now won six straight matches across two years.

"I'm over the moon. Thank you, guys. You guys rocked today. Let's go, New York," Navarro said, calling the Grandstand "my home" and adding, of the physical toll of the season that had disrupted her year: "The tour is long, and it takes it out of you. It's super important to take care of yourself, and then worry about you as a tennis player."

Muchova did not address her exit in immediate public remarks. Her season overall still stands as the best of her career by ranking and results, even with Friday's early departure from the year's final major.

What happens next

Navarro is scheduled to play Kalinskaya on Sunday for a place in the quarterfinals, with the winner likely to face either Noskova or Marta Kostyuk, who are set for a rematch of their Wimbledon semifinal. Should Navarro keep winning, matching or bettering her 2024 semifinal run would cap a season that, only a few months removed from an extended layoff, has already produced a title and two finals. For Muchova, attention turns to the tour's fall Asian swing and the season-ending push to hold a top-10 ranking that, regardless of Friday's result, still represents the best of her career. Play continues through the second week at the USTA Billie Jean King National Tennis Center in Queens, with the women's singles final scheduled for the second Saturday of the tournament.