Play It to the Bone

• 1999 comedy-drama starring Antonio Banderas and Woody Harrelson
• Plot (from IMDb): Two aging fighters in Los Angeles, friends, get a call from a Las Vegas promoter because his undercard fighters for a Mike Tyson bout that night are suddenly unavailable. He wants them to box each other. They agree as long as the winner gets a shot at the middleweight title. They enlist Gloria, Cesar's current and Vinnie's ex-girlfriend, to drive them to Vegas. On the trip, we see flashbacks to their previous title shots, their competitive friendship, and Gloria's motivational wiles. (She has her own entrepreneurial dreams.) The fight itself is historic: ten rounds of savagery and courage.
• IMDb link