24‑Jun‑1974 | Wimbledon | Grass | R64 | 119 | 12 | (12)Manuel Orantes [ESP] d. Koch | 6-2 6-4 4-6 6-2 | | | | | | | | | |
1‑Sep‑1972 | South Orange | Hard | QF | | | Manuel Orantes [ESP] d. Koch | 6-2 6-2 | | | | | | | | | |
21‑Mar‑1971 | Caracas | Clay | F | | | Koch d. Manuel Orantes [ESP] | 7-6 6-1 6-3 | | | | | | | | | |
4‑Feb‑1971 | Washington 1 | Carpet | SF | | | Koch d. Manuel Orantes [ESP] | 6-2 6-2 | | | | | | | | | |
2‑Aug‑1970 | Davis Cup EUR SF: BRA vs ESP | | RR | | | Manuel Orantes [ESP] d. Koch | 6-1 6-3 3-6 6-1 | | | | | | | | | |
17‑Feb‑1969 | Macon | Carpet | SF | | | Manuel Orantes [ESP] d. Koch | 7-5 3-6 6-2 | | | | | | | | | |
15‑Apr‑1968 | Madrid | Clay | QF | | | Manuel Orantes [ESP] d. Koch | 8-6 6-4 | | | | | | | | | |
8‑Feb‑1968 | Philadelphia WCT | Carpet | R16 | | | Koch d. Manuel Orantes [ESP] | W/O | | | | | | | | | |