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.

Venus Williams and Reilly Opelka take on Karolina Muchova and Andrey Rublev at 12:30 p.m. ET today, Aug. 19. The first day of the US Open Mixed Doubles tournament is airing on the ESPN+ streaming service. Right now, ESPN+ costs $11.99/month for new subscribers.

Emma Raducanu and Carlos Alcaraz’s all-star partnership was brought to a premature end as they were beaten in the first round of the revamped US Open mixed doubles.

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

No one will be getting an early glimpse at the men’s world No.1 singles player in Flushing this year, nor an 11-time Grand Slam doubles champion.

Sinner had to forfeit his Cincinnati Open singles final against Carlos Alcaraz after five games due to illness.