Updated

The United States began its gold medal defense with a straight-sets victory over Serbia on the first day of the men's volleyball tournament at the London Games.

The Americans defeated Serbia, 25-17, 25-22 and 25-21 in a match that lasted 1 hour, 25 minutes. Next up for the U.S. is Tuesday's Pool B match against Germany, which lost in three sets to Russia on Sunday.

The U.S. won gold at the 2008 Beijing Games despite tragedy striking former head coach Hugh McCutcheon's family. McCutcheon's father-in-law, Todd Bachman, was stabbed to death at a Beijing city landmark early in the competition. McCutcheon is currently coaching the U.S. women at the 2012 Olympics.

Brazil, the silver medalist in Beijing, also won in straight sets in its Pool B opener against Tunisia.

In Pool A action, Bulgaria and Argentina both won in straight sets, defeating Great Britain and Australia, respectively. Poland also won, taking its match with Italy in four sets.