The second semifinal between defending champions Sara Errani/Andrea Vavassori and the all-American, last-minute alternate pairing of Danielle Collins/Christian Harrison is underway, as they bid to join Świątek/Ruud in the mixed doubles finale.

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.