See main article: 1973 ATP Buenos Aires.
| Champ: |  Guillermo Vilas |
| Runner: |  Björn Borg |
| Score: | 3–6, 6–7, 6–4, 6–6 ret. |
| Draw: | 32 |
| Type: | singles doubles |
| Before Name: | ATP Buenos Aires |
| After Name: | South American Championships |
Guillermo Vilas defeated Björn Borg 3–6, 6–7, 6–4, 6–6 after Borg retired to win the 1973 ATP Buenos Aires singles competition. Karl Meiler was the champion but did not defend his title.