The thought of the top men’s and women’s singles players teaming up is one that has often intrigued tennis fans around the world.

Big names fell early and unexpected teams broke through to steal the spotlight on Day 1 of U.S. Open mixed doubles play, headlining an electric opener packed with upsets and standout performances.

Iga Swiatek and Casper Ruud stormed into the US Open Mixed Doubles semifinals after defeating Madison Keys and Frances Tiafoe. They will face Jessica Pegula and Jack Draper, who beat Andreeva/Medvedev.

Carlos Alcaraz and Emma Raducanu face off against Jessica Pegula and Jack Draper in the Mixed Doubles first round today, Aug. 19, at 2 p.m. ET. The first day of the US Open Mixed Doubles tournament is airing on the ESPN+ streaming service.

Swiatek and Ruud thriving as a duo in New York, reaching the US Open mixed doubles semifinal in their team debut.

A full breakdown of the new "reimagined" US Open Mixed Doubles event that kicks off today at the US Open in New York.

Jannik Sinner has withdrawn from the US Open mixed doubles event after retiring from the Cincinnati Open due to illness. Danielle Collins and Christian Harrison will replace Sinner and Katerina Siniakova in the draw.

The No. 1-ranked Sinner, the defending champion in singles at Flushing Meadows, was supposed to compete in mixed doubles with Katerina Siniakova.