Where to Watch A Gunfight (1971)

In Bajo Rio, they pay to see a man kill a bull. Today, they'll pay to see a man kill another man.

Will Tenneray and Abe Cross are two aging, famous gunfighters, both in need of money. Tenneray comes up with the idea to stage a duel to the death in a bullfight arena, with the ticket proceeds going to the winner.