The Knockout on AllMovie

When he tears a ligament in his arm, light heavyweight champion Sandy Donlin (Milton Sills) is forced to take a break from the ring. His friend Parker, a lumber magnate (Claude King) sends him to the North woods to battle against a rival lumber boss. The rival turns out to be Farot (Harlan Knight) and his fetching daughter, Jean (Lorna Duveen), and Parker's schemes are anything but on the up-and-up. Donlin changes alliances and tries to stop his former friend's plans. Parker's men still manage to dynamite the dam, which ties up the Farot lumber for a year. It looks like Jean won't be able to make the mortgage unless Donlin goes back into the ring. The only problem is that Jean has already said she hates fighting and will have nothing to do with pugilists. At the last minute, she has a change of heart, and Donlin wins the bout and makes the payment.