Nikoloz Basilashvili (5), Georgia, def. Facundo Bagnis, Argentina, 6-4, ret.
Joao Sousa, Portugal, def. Pablo Andujar, Spain, 6-1, 6-4.
Christopher O'Connell, Australia, def. Albert Ramos-Vinolas, Spain, 7-6 (5), 6-4.
Thanasi Kokkinakis, Australia, def. Fabio Fognini, Italy, 6-4, 6-3.
Johan Nikles, Switzerland, def. Leandro Riedi, Switzerland, 5-7, 7-6 (3), 7-5.
Richard Gasquet, France, def. Daniil Medvedev (1), Russia, 6-2, 7-6 (5).
Kamil Majchrzak, Poland, def. Marco Cecchinato, Italy, 6-2, 6-3.
Jean-Julien Rojer, Netherlands, and Marcelo Arevalo-Gonzalez (3), El Salvador, def. Philipp Oswald, Austria, and Hans Hach Verdugo, Mexico, 7-5, 6-3.
Ivan Sabanov and Matej Sabanov, Serbia, def. Santiago Gonzalez, Mexico, and Andres Molteni (4), Argentina, 6-7 (5), 6-3, 10-4.