The Jeffries-Sharkey Contest (1899)
James J. Jeffries and Sailor Sharkey battled for the heavyweight title while two major movie companies were also battling. You can read about the full story elsewhere but basically Edison was able to arrange the filming of this match but while shooting it they discovered that Biograph had snuck into the arena and was also filming it. Apparently this led to countless battles to get the films developed and into movie places.
Both companies had their versions released and I believe the one I viewed was from Edison. From what I've read, Edison was filming by the stage while Biograph was in the stands and the footage I watched was certainly ringside. There's a little over three minutes worth of the boxing footage and for the most part it's entertaining. Fans of boxing will certainly enjoy getting to see these champions so we can be grateful for both studios doing what they did.