Fighting Blood (1923)

Al Santell silent sports boxing comedy series starring George O'Hara, and all star cast: Kit Guard, Al Cooke, Clara Horton, Mabel Van Buren, and Clark Gable (in one of his 14 uncredited roles prior to making his real debut in 1931's "The Painted Desert"). Note that this was one of a series of boxing films with the same characters, and each new film in the series was called a "round" (appropriate for a series of boxing movies!), but these movies were not serials, just connected by having the same characters. This card is the 3rd round, "Six Second Smith".

Unfortunately the movie Fighting Blood is not yet available on HBO Max.