Allison Schmitt ran down Alicia Coutts on the final leg Wednesday as the United States emerged victorious in a duel with Australia for Olympic gold in the women's 4x200m freestyle relay.
Missy Franklin, Dana Vollmer, Shannon Vreeland and Schmitt won in an Olympic record of 7min 42.92sec, Schmitt dealing the knockout blow in a race that had been neck-and-neck much of the way.
Three of the US swimmers -- Schmitt, Vollmer and Franklin -- claimed their second gold medals of the Games, Schmitt adding the relay title to her individual 200m free crown.
"I knew it was close, it had been close throughout the race," said Schmitt, who hit the water trailing slightly but gradually gained ground on Coutts and swam away with it in the final 100m.
"I had a good 200m race, so I just wanted to feed off the energy from last night and bring home the gold in the relay," she said.
Vollmer added the relay gold to the 100m fly she won in world-record time, and 17-year-old Franklin had won the 100m backstroke.
Bronte Barrat, Melanie Schlanger, Kylie Palmer and Coutts took silver in 7:44.41, and France claimed bronze in 7:47.49.