Michael Phelps won his record eighth gold medal at the Beijing Olympics as a member of the victorious US 4x100-meter medley relay team, breaking a tie with Mark Spitz for most golds in a single game. Aaron Peirsol, Brendan Hansen, Phelps and Jason Lezak won in a world-record of 3 minutes, 29.34 seconds Sunday, lowering the old mark of 3:30.68 set four years ago in Athens. The Americans swept the men's relays in Beijing, with Phelps leading off in the 400 and 800 freestyle relays. Lezak anchored the 400 free to a narrow victory over France to preserve Phelps's historic bid. Australia took the silver in 3:30.04, and Japan earned the bronze in 3:31.18.