RIO DE JANEIRO - Ryan Murphy maintained America's dominance in the men's 100m backstroke at the Olympics with victory on Monday in a Games-record 51.97 seconds.

China's Xu Jiayu finished in 52.31sec to win silver at the Olympic Aquatics Stadium. American David Plummer took bronze (52.40sec).

The last non-American swimmer to win this event was Canadian Mark Tewksbury at the 1992 Barcelona Games.

"The adrenaline is going so hard in me right now. I don't even feel tired. I'm so excited," said Murphy, 21. "This means everything to me. I've been swimming for 16 years. It's a dream come true."