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.

Jannik Sinner has withdrawn from the U.S. Open mixed doubles event, where he was going to partner Katerina Siniakova, a day after illness forced the world number one to retire five games into his Cincinnati Open final.

Viewers in the UK can watch the mixed doubles at the US Open live on Sky Sports Tennis. The event is being streamed on ESPN in the United States. The full 16-team field was decided by the top-8 singles rankings combined, and eight wildcard picks.

While Jack Draper and Jessica Pegula may have said all of four words to each other before teaming up for this week’s U.S. Open mixed doubles tournament, the two already sound like an “old married couple.

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