The Electric Horseman(1979)

He's a washed-up loser. But sometimes losers can be heroes...

A former champion rodeo rider is reduced to using his saddle skills to promote a breakfast cereal in a gaudy Las Vegas show. When he's asked to perform with a $12 million horse, he discovers it is being doped to remain docile. He flees into the desert astride the beast in an act of defiance. A story-hungry female reporter gives chase.