Head to head
2
Hard
1
2
Grass
0
Onny Parun's wins on the left · Ross Case's on the right · bar lengths share one scale
All meetings (5)
| 1974 | Jakarta | Hard | QF | Onny Parun | 7-5 6-4 |
| 1974 | Sydney-2 | Hard | R16 | Onny Parun | 6-2 7-6 |
| 1974 | Auckland | Grass | SF | Onny Parun | 7-5 6-3 6-1 |
| 1973 | US Open | Grass | R16 | Onny Parun | 6-4 6-1 4-6 6-4 |
| 1971 | Berkeley WCT | Hard | R64 | Ross Case | 3-6 6-3 7-6 |
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.