On a searing hot day, Round 1 of doubles action kicked off with one scorching upset on the men’s side: Top seeds Oliver Marach and Mate Pavić fell in three tight sets to Leonardo Mayer and João Sousa, 3-6, 7-6, 7-5. The teams stayed on serve for most of the decider until Marach double faulted at 5-5 on break point, allowing Sousa to serve out the match.

Reigning French Open champions and No. 9 seeds Pierre-Hugues Herbert and Nicolas Mahut survived a scare of their own, coming through in a third-set tiebreak over Nicholas Monroe and John-Patrick Smith. Last year’s US Open champions, No. 6 seeds Jean-Julien Rojer and Horia Tecău, had an easier go of it with a 6-3, 6-4 win over Antonio Šančić and Sander Arends.

American Mackenzie McDonald lost his singles match in five sets to Robin Haase on Tuesday but advanced to the second round in men's doubles with his partner Yoshihito Nishioka, who also lost his singles match Tuesday… to a guy named Roger Federer. Brothers Christian and Ryan Harrison also advanced.

On the women’s side, the all-American team of Jennifer Brady and Asia Muhammad took out 2018 Wimbledon finalists and No. 8 seeds Kveta Peschke and Nicole Melichar in three tight sets. At least one more all-American team was guaranteed entry into the second round, as Caroline Dolehide and Christina McHale took on Varvara Lepchenko and Bernarda Pera, with Dolehide and McHale dropping just three games on the way to a 6-2, 6-1 victory.

Elsewhere, top seeds Barbora Krejčíková and Kateřina Siniaková, the reigning French and Wimbledon champions, were tested and taken to a tiebreak in the first set of their match against the team of Kateryna Bondarenko and Aleksandra Krunic but rolled in the second, 6-1. No. 2 seeds Kiki Mladenovic and Timea Babos also won in straight sets.

Other teams who moved safely into the second round include Sam Stosur and Shuai Zhang; Timea Bacszinsky and Vera Zvonareva; and Su-Wei Hsieh and Aryna Sabalenka.