SYDNEY, Australia (AP) -- American Tom Malchow won the 200-meter butterfly Tuesday, lowering his own Olympic record for the third time in two days and giving the U.S. team its sixth swimming gold medal.

 Malchow, of St. Paul, Minn., was first in 1 minute, 55.35 seconds, bettering his own Olympic mark of 1:56.02 set in Monday's semifinals.

 Cristina Teuscher of New Rochelle, N.Y., added to the Americans' haul with a bronze in the 200 individual medley. The United States has 12 medals in four days at the Olympic pool.

 In the 200 butterfly, Denys Sylant'yev of Ukraine won silver in 1:55.76. Justin Norris of Australia took bronze in 1:56.17.

 Michael Phelps of Baltimore, a 15-year-old who is the youngest male U.S. Olympic swimmer since 1932, finished fifth in 1:56.50.

 "I wish I was a little faster coming home, but I did my best," said Phelps, who swam faster in the preliminaries and semifinals.

 Malchow added gold to the silver he won in the same event in Atlanta, where at 19 he was the youngest man on the U.S. swimming team.

 Having lowered his Olympic record in the prelims and again in the semis, Malchow fell 17 one-hundreths short of his world record of 1:55.18 set in June at a meet in Charlotte, N.C.

 "For four years, I've wanted that moment," he said. "The world record was a little taste of how it was going to be, but that was unreal. I can't think of anything better."

 After trying basketball and baseball, Malchow had learned to swim because he could do so inside, away from whatever pollutants would bother his asthma.

 Phelps followed his usual pattern of lagging well back early but, this time, he failed to make much of a dent. He was eighth at 150 meters and pulled into fifth at the wall.

 In the women's 200 individual medley, Yana Klochkova won her second gold of the games -- the first two in Ukraine's swimming history. She won in an Olympic record 2:10.68, breaking the 8-year-old mark of 2:11.65 set by Lin Li of China.

 Klochkova's first gold came in the 400 IM.

 Beatrice Caslaru of Romania took silver in 2:12.57. She claimed bronze in the 400 IM Saturday.

 Teuscher won bronze in 2:13.32.

 "I'm happy I stuck it in there for a medal," she said. "You can't complain when you get a medal in the Olympics."

 Gabrielle Rose of Memphis, Tenn., was seventh at 2:14.82.

 The evening began with a bang thanks to Dutchman Pieter van den Hoogenband. One night after winning gold in the 200 freestyle, tying his own world record, Van den Hoogenband broke the world mark in the 100 freestyle semifinals.

 He swam 47.84 seconds, lowering Australian Michael Klim's mark of 48.18.

 Klim swam in the previous heat and was almost a second behind in 48.80. Alexander Popov of Russia, the two-time defending Olympic champion, was third-quickest in 48.84.

 Neil Walker of Verona, Wis., qualified fifth in 49.04. Gary Hall Jr. of Phoenix, the silver medalist in Atlanta, made Wednesday's final by finishing sixth in 49.13.

 "It's amazing," Walker said of the Dutchman. "I can't even fathom how fast that is. I'm sure he'll be faster tomorrow."

 Australian Susie O'Neill touched off a raucous celebration by winning gold in the 200 freestyle. The crowd of 17,500 at Sydney International Aquatic Center chanted "Susie, Susie" as O'Neill churned to the finish in 1:58.24.

 Martina Moravcova of Slovakia earned her second silver medal of these games in 1:58.32. She won silver in the 100 butterfly Sunday.

 Claudia Poll of Costa Rica, the defending Olympic champion, settled for bronze in 1:58.81. She also won bronze in the 400 free Sunday.