Head to head
3
Hard
0
2
Clay
1
0
Grass
2
Kei Nishikori's wins on the left · Karen Khachanov's on the right · bar lengths share one scale
Momentum
Running lead across all meetings, oldest to newest (walkovers excluded).
All meetings (8)
| 2025 | Geneva | Clay | R16 | Karen Khachanov | 7-5 2-5 RET |
| 2024 | Hong Kong | Hard | R16 | Kei Nishikori | 4-6 6-3 7-5 |
| 2021 | Roland Garros | Clay | R64 | Kei Nishikori | 4-6 6-2 2-6 6-4 6-4 |
| 2021 | Madrid Masters | Clay | R64 | Kei Nishikori | 6-7(6) 6-2 6-2 |
| 2018 | Vienna | Hard | R16 | Kei Nishikori | 6-2 6-2 |
| 2018 | Halle | Grass | R16 | Karen Khachanov | 6-2 6-2 |
| 2017 | Halle | Grass | R16 | Karen Khachanov | 3-2 RET |
| 2016 | US Open | Hard | R64 | Kei Nishikori | 6-4 4-6 6-4 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.