Stadium: Court 5 Round: 26 Ground: Hardcourt outdoor
| ATP Sao Paulo MD | 2018/03/04 17:20 | Koolhof/Sitak v Delbonis/Gonzalez | 4-6,2-6 |
| ATP Sao Paulo MD | 2018/03/03 20:00 | Berlocq/Kicker v Koolhof/Sitak | 3-6,3-6 |
| ATP Sao Paulo MD | 2018/02/28 20:45 | Koolhof/Sitak v C Baena/Garcia-Lopez | 7-5,6-4 |
| ATP Sao Paulo MD | 2018/02/27 23:10 | Koolhof/Sitak v Arends/Begemann | 6-4,7-6 |
| ATP - Delray Beach - Herredouble | 2018/02/21 16:00 | Koolhof/Sitak v Lipsky/Sharan | 6-7,2-6 |
| ATP - New York - Herredouble | 2018/02/18 18:00 | Koolhof/Sitak v Mirnyi/Oswald | 4-6,6-4,6-10 |
| ATP - New York - Herredouble | 2018/02/18 03:05 | Koolhof/Sitak v Albot/Basilashvili | 6-4,6-3 |
| ATP - New York - Herredouble | 2018/02/16 22:30 | Chardy/Martin v Koolhof/Sitak | 4-6,6-3,6-10 |