Jakub Mensik, left, of the Czech Republic, and Karolina Muchova, of the Czech Republic, react during the mixed doubles final match against Belinda Bencic, of Switzerland, and Flavio Cobolli, of Italy, at the U.S. Open tennis championships Wednesday, Aug. 26, 2026, in New York. (AP Photo/Frank Franklin II)

Czech Republic's Jakub Mensik celebrates after he and partner Czech Republic's Karolina Muchova beat Switzerland's Belinda Bencic and Italy's Flavio Cobolli in the mixed doubles final tennis match of the 2026 US Open tennis tournament at the USTA Billie Jean King National Tennis Center in New York on August 26, 2026. (Photo by CHARLY TRIBALLEAU / AFP via Getty Images)

Czech Republic's Karolina Muchova and Czech Republic's Jakub Mensik celebrate after they beat Switzerland's Belinda Bencic and Italy's Flavio Cobolli in the mixed doubles final tennis match of the 2026 US Open tennis tournament at the USTA Billie Jean King National Tennis Center in New York on August 26, 2026. (Photo by TIMOTHY A. CLARY / AFP via Getty Images)

NEW YORK, NEW YORK - AUGUST 26: Jakub Mensik of Czechia celebrates with partner Karolina Muchova of Czechia (not pictured) after defeating Belinda Bencic of Switzerland and Flavio Cobolli of Italy in the Mixed Doubles Final of the US Open at USTA Billie Jean King National Tennis Center on August 26, 2026 in New York City. (Photo by Caleb Bowlin/Getty Images)

Czech Republic's Jakub Mensik celebrates after he and partner Czech Republic's Karolina Muchova beat Switzerland's Belinda Bencic and Italy's Flavio Cobolli in the mixed doubles final tennis match of the 2026 US Open tennis tournament at the USTA Billie Jean King National Tennis Center in New York on August 26, 2026. (Photo by TIMOTHY A. CLARY / AFP via Getty Images)

NEW YORK, NEW YORK - AUGUST 26: Karolina Muchova of Czechia returns a shot while playing with Jakub Mensik of Czechia during the Mixed Doubles Final of the US Open against Belinda Bencic of Switzerland and Flavio Cobolli of Italy at USTA Billie Jean King National Tennis Center on August 26, 2026 in New York City. (Photo by Caleb Bowlin/Getty Images)

Czech Republic's Jakub Mensik celebrates after he and partner Czech Republic's Karolina Muchova beat Switzerland's Belinda Bencic and Italy's Flavio Cobolli in the mixed doubles final tennis match of the 2026 US Open tennis tournament at the USTA Billie Jean King National Tennis Center in New York on August 26, 2026. (Photo by TIMOTHY A. CLARY / AFP via Getty Images)

Czech Republic's Jakub Mensik celebrates after he and partner Czech Republic's Karolina Muchova beat Switzerland's Belinda Bencic and Italy's Flavio Cobolli in the mixed doubles final tennis match of the 2026 US Open tennis tournament at the USTA Billie Jean King National Tennis Center in New York on August 26, 2026. (Photo by TIMOTHY A. CLARY / AFP via Getty Images)