Diana Lopez knocked out of Olympics in opener

American Diana Lopez, a member of the Lopez taekwondo family, was knocked out of the Olympics in her first bout Thursday.

Lopez lost in a sudden-death fourth round to China's Hou Yuzhuo, the two-time world champion in the under 57 kilogram division.

Lopez was the 2008 bronze medalist in the event. Her brother Steven, a two- time Olympic gold medalist, is also in London to compete in the under 80kg event.