Ryan Murphy extends U.S. gold streak in 100 backstroke to 6

The United States' winning streak in the 100-meter backstroke continued Monday as Ryan Murphy won with an Olympic-record 51.97 seconds for the Americans' sixth straight gold medal in the event.

China's Jiayu Xu finished second (52.31), while 30-year-old American David Plummer took home bronze (52.40).

Plummer, a first-time Olympian at age 30, becomes the fourth-oldest swimmer, male or female, to medal in a Games debut and the oldest to do so since 1912.

ESPN Stats & Information contributed to this report.