Swimming at the 1964 Tokyo Summer Games:

Marilyn Ramenofsky of the United States had set three world records in this event earlier in 1964 and came to Tokyo as the favorite. In fact it was thought that the Americans could sweep the event, with Ginny Duenkel, already a bronze medalist in Tokyo in the 100 back, and [Terri Stickles]. Ramenofsky led the final through 175 metres, when she was caught by Duenkel who gradually pulled away from her teammate. Duenkel held on to upset Ramenofsky and win the gold medal, with Stickles completing the American sweep by outlasting Australia’s Dawn Fraser. Duenkel posted 4:43.3, a personal best for her by 3/10ths of a second, but well off Ramenofsky’s world record of 4:39.5.