Alex de Minaur (9), Australia, def. Lucas Pouille, France, walkover.
Alexander Zverev (4), Germany, def. Cameron Norrie, Britain, 6-4, 6-4, 7-6 (15).
Barbora Krejcikova (31), Czechia, def. Jessica Bouzas Maneiro, Spain, 6-0, 4-3, ret.
Jelena Ostapenko (13), Latvia, def. Bernarda Pera, United States, 6-1, 6-3.
Anna Kalinskaya (17), Russia, def. Liudmila Samsonova (15), Russia, 7-6 (4), 6-2.
Bethanie Mattek-Sands and Sofia Kenin (14), United States, def. Zhang Shuai, China, and Miyu Kato, Japan, 6-1, 6-4.