Head to head
2
Hard
3
Ivo Karlovic's wins on the left · Kei Nishikori's on the right · bar lengths share one scale
All meetings (5)
| 2019 | Australian Open | Hard | R64 | Kei Nishikori | 6-3 7-6(6) 5-7 5-7 7-6(7) |
| 2016 | US Open | Hard | R16 | Kei Nishikori | 6-3 6-4 7-6(4) |
| 2014 | Memphis | Hard | F | Kei Nishikori | 6-4 7-6(0) |
| 2013 | Delray Beach | Hard | R32 | Ivo Karlovic | 5-4 RET |
| 2012 | Davis Cup WG R1: JPN vs CRO | Hard | RR | Ivo Karlovic | 6-4 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.