Stadium: Court 1 Round: 26 Ground: Clay
| ATP Delray Beach MD | 2018/02/21 16:00 | Koolhof/Sitak v Lipsky/Sharan | 6-7,2-6 |
| ATP New York MD | 2018/02/18 18:00 | Koolhof/Sitak v Mirnyi/Oswald | 4-6,6-4,6-10 |
| ATP New York MD | 2018/02/18 03:05 | Koolhof/Sitak v Albot/Basilashvili | 6-4,6-3 |
| 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 |