Stadium: Stadium Court Round: 28 Ground: Hardcourt outdoor
| ATP New York MD | 2018/02/16 22:30 | Chardy/Martin v Koolhof/Sitak | 4-6,6-3,6-10 |
| ATP New York MD | 2018/02/14 18:00 | Koolhof/Sitak v Nestor/Skupski | 6-3,6-1 |
| ATP Montpellier MD | 2018/02/08 13:45 | Koolhof/Sitak v Arends/Sancic | 6-3,4-6,5-10 |
| ATP Montpellier MD | 2018/02/07 19:25 | Dodig/Ram v Koolhof/Sitak | 6-2,5-7,0-10 |
| Challenger Newport Beach MD | 2018/01/24 23:50 | Koolhof/Sitak v Huey/Kudla | 2-6,1-6 |
| Australian Open MD | 2018/01/19 01:30 | Koolhof/Sitak v Marach/Pavic | 7-6,4-6,4-6 |
| Australian Open MD | 2018/01/17 01:40 | Gojowczyk/Mayer v Koolhof/Sitak | 2-6,1-6 |
| ATP Auckland MD | 2018/01/09 08:30 | Koolhof/Sitak v Klaasen/Venus | 1-6,7-6,7-10 |
| ATP New York MD | 2018/02/13 22:45 | Monroe/Smith v Albot/Basilashvili | 6-7,4-6 |