On August 17, 1938 Ambers met Henry Armstrong in an historic fight for the world lightweight title. Armstrong was attempting to become the first fighter in history to win and hold three world titles simultaneously. In a great fight, Ambers was knocked down twice, in the fifth and sixth rounds, and appeared badly beaten. Ambers mounted a great comeback in the later half of the match, but lost the controversial split decision. Armstrong was penalized three rounds in the close bout for fouls. Ambers lost the title for a year, until regaining it in a rematch one year later.