ATHENS, Greece -- Michael Phelps grabbed his head in disbelief, then thrust his left fist in the air. He's an Olympic champion - just like Mark Spitz. Phelps began his quest to overtake Spitz's 1972 record haul of seven gold medals with a dominating performance in the 400-meter individual medley, breaking his own world record Saturday night and claiming the first U.S. gold medal of the Athens Games.
Ian Thorpe won his second straight gold in the 400 freestyle - a race he got into only through the generosity of an Australian teammate - but Jenny Thompson was denied her record-tying ninth gold medal when she gave up the lead to Australia on the final leg of the 400 free relay.
"It was a change of pace for me to be passed by someone," Thompson said. "It's usually the other way around."
Still, it was a good night for the powerful American team, which began eight days in the Olympic pool with a 1-2 finish. Phelps touched the wall in 4 minutes, 8.26 seconds, while teammate Erik Vendt was more than 3 1/2 seconds behind but good enough for silver at 4:11.81.
"I'm a little bit less nervous," said Phelps, 19, of Baltimore. "I've got one off my shoulders and can relax a little bit."
It was a rousing start to the much-anticipated Olympic meet, but Phelps is just getting warmed up. He will likely swim in eight events, giving him a chance to break Spitz's record at the Munich Games.
So far, Phelps is following the script of the greatest swimmer in Olympic history. All seven of Spitz's wins were in record time.
Thorpe almost missed the 400 free - his best event - when he inexplicably fell off the starting block at the Australian trials, earning an automatic disqualification. But he got in when teammate Craig Stevens gave up his spot.
Thorpe barely held off another countryman, Grant Hackett, to win in 3:43.10. American Klete Keller took bronze for the second straight Olympics, setting an American record of 3:44.11.