By surface
| Surface | Giuseppe Merlo | Koji Watanabe |
|---|---|---|
| Clay | 0 | 1 |
All meetings (1)
| Date | Tour | Tournament | Round | Surface | Winner | Set 1 | Set 2 | Set 3 | Set 4 | Set 5 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1968-07-21 | ATP | Gstaad | Round of 32 | Clay | Koji Watanabe | 0-1 |
| Surface | Giuseppe Merlo | Koji Watanabe |
|---|---|---|
| Clay | 0 | 1 |
| Date | Tour | Tournament | Round | Surface | Winner | Set 1 | Set 2 | Set 3 | Set 4 | Set 5 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1968-07-21 | ATP | Gstaad | Round of 32 | Clay | Koji Watanabe | 0-1 |