| | | | |
|  Croatia |  India | |
|
RANK 277 | Borna Gojo | 3-6 6-4 6-2 | Prajnesh Gunneswaran | RANK 132 |
RANK 37 | Marin Cilic | 7-6(8) 7-6(8) | Ramkumar Ramanathan | RANK 182 |
| Mate Pavic / Franko Skugor | 3-6 7-6(9) 5-7 | Rohan Bopanna / Leander Paes | |
RANK 37 | Marin Cilic | 6-0 6-1 | Sumit Nagal | RANK 127 |
RANK 277 | Borna Gojo | NOT PLAYED | Ramkumar Ramanathan | RANK 182 |
| | | | |
| | | | |
|  Hungary |  Belgium | |
|
RANK 76 | Attila Balazs | 7-5 6-7(4) 4-6 | Ruben Bemelmans | RANK 222 |
RANK 84 | Marton Fucsovics | 6-2 5-7 6-4 | Kimmer Coppejans | RANK 154 |
| Attila Balazs / Marton Fucsovics | 6-3 1-6 4-6 | Sander Gille / Joran Vliegen | |
RANK 76 | Attila Balazs | 6-3 6-0 | Kimmer Coppejans | RANK 154 |
RANK 84 | Marton Fucsovics | 6-7(7) 6-4 6-2 | Ruben Bemelmans | RANK 222 |
| | | | |
| | | | |
|  Colombia |  Argentina | |
|
RANK 148 | Daniel Elahi Galan | 6-1 6-4 | Leonardo Mayer | RANK 118 |
RANK 292 | Santiago Giraldo | 7-6(6) 3-6 2-6 | Juan Ignacio Londero | RANK 62 |
| Juan-Sebastian Cabal / Robert Farah | 6-3 6-7(3) 7-5 | Maximo Gonzalez / Horacio Zeballos | |
RANK 148 | Daniel Elahi Galan | 6-3 6-4 | Juan Ignacio Londero | RANK 62 |
RANK 292 | Santiago Giraldo | NOT PLAYED | Leonardo Mayer | RANK 118 |
| | | | |
| | | | |
|  United States |  Uzbekistan | |
|
RANK 38 | Reilly Opelka | 6-2 7-5 | Denis Istomin | RANK 156 |
RANK 24 | Taylor Fritz | 6-1 6-2 | Sanjar Fayziev | RANK 498 |
| Bob Bryan / Mike Bryan | 6-3 6-4 | Sanjar Fayziev / Denis Istomin | |
RANK 57 | Tommy Paul | 6-3 6-0 | Denis Istomin | RANK 156 |
RANK 38 | Reilly Opelka | NOT PLAYED | Sanjar Fayziev | RANK 498 |
| | | | |
| | | | |
|  Australia |  Brazil | |
|
RANK 63 | Jordan Thompson | 6-4 6-4 | Thiago Monteiro | RANK 82 |
RANK 43 | John Millman | 4-6 7-6(0) 6-2 | Thiago Seyboth Wild | RANK 113 |
| James Duckworth / John Peers | 7-5 5-7 6-7(6) | Marcelo Demoliner / Felipe Meligeni Rodrigues Alves | |
RANK 43 | John Millman | 6-7(6) 7-6(3) 7-6(3) | Thiago Monteiro | RANK 82 |
RANK 63 | Jordan Thompson | NOT PLAYED | Thiago Seyboth Wild | RANK 113 |
| | | | |
| | | | |
|  Italy |  South Korea | |
|
RANK 11 | Fabio Fognini | 6-0 6-3 | Duckhee Lee | RANK 251 |
RANK 79 | Gianluca Mager | 6-3 7-5 | Ji Sung Nam | RANK 238 |
| Simone Bolelli / Fabio Fognini | 6-3 6-1 | Ji Sung Nam / Min-Kyu Song | |
RANK 86 | Stefano Travaglia | 6-0 6-1 | Yunseong Chung | RANK 333 |
RANK 79 | Gianluca Mager | NOT PLAYED | Duckhee Lee | RANK 251 |
| | | | |
| | | | |
|  Germany |  Belarus | |
|
RANK 34 | Jan-Lennard Struff | 6-4 6-4 | Ilya Ivashka | RANK 138 |
RANK 73 | Philipp Kohlschreiber | 6-4 5-7 6-7(3) | Egor Gerasimov | RANK 68 |
| Kevin Krawietz / Andreas Mies | 6-4 7-6(5) | Ilya Ivashka / Andrei Vasilevski | |
RANK 34 | Jan-Lennard Struff | 6-3 6-2 | Egor Gerasimov | RANK 68 |
RANK 92 | Dominik Koepfer | 6-0 6-2 | Daniil Ostapenkov | RANK |
| | | | |
| | | | |
|  Kazakhstan |  Netherlands | |
|
RANK 91 | Mikhail Kukushkin | 4-6 7-6(2) 3-6 | Robin Haase | RANK 169 |
RANK 51 | Alexander Bublik | 7-6(4) 7-6(4) | Tallon Griekspoor | RANK 196 |
| Andrey Golubev / Aleksandr Nedovyesov | 6-3 6-3 | Robin Haase / Jean-Julien Rojer | |
RANK 51 | Alexander Bublik | 7-6(4) 6-1 | Robin Haase | RANK 169 |
RANK 91 | Mikhail Kukushkin | NOT PLAYED | Tallon Griekspoor | RANK 196 |
| | | | |
| | | | |
|  Slovakia |  Czech Republic | |
|
RANK 121 | Jozef Kovalik | 3-6 5-7 | Jiri Vesely | RANK 64 |
RANK 95 | Andrej Martin | 4-6 4-6 | Lukas Rosol | RANK 179 |
| Filip Polasek / Igor Zelenay | 6-4 6-4 | Jonas Forejtek / Zdenek Kolar | |
RANK 95 | Andrej Martin | 6-4 5-7 5-7 | Jiri Vesely | RANK 64 |
RANK 121 | Jozef Kovalik | NOT PLAYED | Lukas Rosol | RANK 179 |
| | | | |
| | | | |
|  Austria |  Uruguay | |
|
RANK 85 | Dennis Novak | 6-2 6-4 | Martin Cuevas | RANK 487 |
RANK 168 | Jurij Rodionov | 7-6(7) 3-6 6-7(5) | Pablo Cuevas | RANK 60 |
| Oliver Marach / Jurgen Melzer | 4-6 6-3 7-5 | Ariel Behar / Pablo Cuevas | |
RANK 85 | Dennis Novak | 2-6 6-3 6-4 | Pablo Cuevas | RANK 60 |
RANK 168 | Jurij Rodionov | NOT PLAYED | Martin Cuevas | RANK 487 |
| | | | |
| | | | |
|  Japan |  Ecuador | |
|
RANK 117 | Go Soeda | 5-7 6-7(3) | Emilio Gomez | RANK 151 |
RANK 90 | Yasutaka Uchiyama | 6-7(4) 6-2 6-7(8) | Roberto Quiroz | RANK 276 |
| Ben McLachlan / Yasutaka Uchiyama | 6-7(3) 3-6 | Gonzalo Escobar / Diego Hidalgo | |
RANK 90 | Yasutaka Uchiyama | NOT PLAYED | Emilio Gomez | RANK 151 |
RANK 117 | Go Soeda | NOT PLAYED | Roberto Quiroz | RANK 276 |
| | | | |
| | | | |
|  Sweden |  Chile | |
|
RANK 67 | Mikael Ymer | 6-2 6-3 | Marcelo Tomas Barrios Vera | RANK 282 |
RANK 202 | Elias Ymer | 4-6 3-6 | Alejandro Tabilo | RANK 173 |
| Markus Eriksson / Robert Lindstedt | 6-4 6-4 | Marcelo Tomas Barrios Vera / Alejandro Tabilo | |
RANK 67 | Mikael Ymer | 3-6 7-5 6-3 | Alejandro Tabilo | RANK 173 |
RANK 202 | Elias Ymer | NOT PLAYED | Marcelo Tomas Barrios Vera | RANK 282 |
| | | | |