ROME—Coming into the Internazionali BNL d'Italia, John Isner had just reached the doubles semifinals of Madrid alongside Hubert Hurkacz—his Miami Open-winning partner.

This week, the American once again entered doubles but opted to mix it up as one half of a highly anticipated duo. One of the ATP’s ‘servebots’, 6'10" Isner joined forces with 5'7" Diego Schwartzman, a perennial ‘returnbot’, for the first time in Rome.

Owning contrasting builds and strengths, the combination of differences resulted in a winning debut Monday at the Foro Italico. After a slow start, Isner and Schwartzman pulled away to defeat Andres Molteni and Santiago Gonzalez, 5-7, 6-3 [10-1].

The victory marked Isner’s 20th on the doubles court this season. He and Schwartzman—who like Isner is also a Fila ambassador—await Reilly Opelka and Tommy Paul or fifth seeds Juan Sebastian Cabal and Robert Farah.