Head to head
3
Hard
1
1
Grass
0
Kei Nishikori's wins on the left · Gael Monfils's on the right · bar lengths share one scale
All meetings (5)
| 2018 | US Open | Hard | R64 | Kei Nishikori | 6-2 5-4 RET |
| 2017 | Canada Masters | Hard | R32 | Gael Monfils | 6-7(4) 7-5 7-6(6) |
| 2016 | Rio Olympics | Hard | QF | Kei Nishikori | 7-6(4) 4-6 7-6(6) |
| 2016 | Miami Masters | Hard | QF | Kei Nishikori | 4-6 6-3 7-6(3) |
| 2014 | Halle | Grass | R16 | Kei Nishikori | 6-1 3-6 6-3 |
Methodology
Head-to-head totals and surface splits exclude walkovers (no match was played), which follows ATP convention — walkover meetings still appear in the match list. The momentum chart plots the running lead across all counted meetings, oldest to newest.