Saturday, August 23, 2008 - 11:14 PM

The United States has won gold medals in both the men's and women's 4x400 metres relays at the Beijing Olympics.

The men's team won for the seventh time in a row in an Olympic record 2 minutes and 55.39 seconds.

Beijing 400m Olympic champion LaShawn Merritt, 400m hurdles Olympic champion Angelo Taylor, 400m bronze medallist David Neville and two-time world 400m champion Jeremy Wariner broke the old mark of 2:55.74, set by US men in 1992.

Bahamas was second in 2:58.03 with Russia third in 2:58.06.

The Australian team of Sean Wroe, John Steffensen, Clinton Hill, Joel Milburn came in sixth. Australia won silver in the event in Athens four years ago.

In the women's, Sanya Richards surged past her Russian rival in the final few metres to help the United States win the gold medal.

Richards teamed up with Mary Wineberg, Allyson Felix and Monique Henderson to win in a time of 3 minutes and 18.54 seconds.

Russia finished second in 3:18.82 after Anastasia Kapachinskaya started the last leg with a handy lead over Richards.

Jamaica won the bronze medal in 3:20.40.