Michael Phelps is quick to six

BEIJING — Six was quick for Michael Phelps — another gold medal, another world record.

The American swimmer splashed his way to his sixth gold of these Olympic Games on Friday morning in the 200 individual medley, breaking his world record with a time of 1 minute, 54.23 seconds.

Phelps took the lead in the first quarter of the race and never came close to relinquishing it. "I just wanted to step on it in the first 50 a little bit and try and get out to an early lead," Phelps said. "I knew in the first half if I got a big enough lead I thought I could hang on, and that's all I wanted to do."

That was just part of a star-spangled performance at the Water Cube, where the Americans won three of the four finals.

Phelps' victory also extended his career Olympic haul to 12 gold medals — more than any other Olympic athlete in history. In six events in China, Phelps has set six world records — four in individual events and two in relays. With a goal of winning eight golds in eight events, Phelps will swim his final two events — the 100 butterfly and the 400 medley relay — in the next two days.

The biggest obstacle to hitting the "Great Eight" jackpot for Phelps will likely be the 100 butterfly, where U.S. teammate Ian Crocker has beaten him three times in their careers (but not since 2005). Crocker also holds the world record in the event.

From his pre-race iPod to the way he snaps his arms together three times on the starting blocks just before the race, Phelps' habits have become familiar to an American public that sees him race on TV practically every night. He has made winning a habit, too.

The main competition for Phelps in the 200 individual medley was U.S. teammate Ryan Lochte. Phelps doesn't need any breaks, but he got one anyway in that race. Lochte won a gold medal in the 200 backstroke only 28 minutes before the 200 IM.

He edged Aaron Peirsol at the wall and set a world record. Peirsol was the ruler of that event for seven years, going undefeated from 2001 to 2007, until Lochte beat him in the world championships. Peirsol had then edged Lochte at the 2008 U.S. Olympic trials.

After Friday's win, Lochte had to jump right back in the water to face Phelps.

The difficult sequence obviously took a toll on Lochte. He is the second-best swimmer in the world in the event by time, but he struggled to a third-place finish in the 200. "I laid everything I had out there," Lochte said.

Phelps said, "I knew that was a hard double for Ryan."

Hungary's Laszlo Cseh took silver.

Soni wins gold

America's Rebecca Soni won the gold medal in the 200 breaststroke, setting a world record at 2:20.22. Soni had already won a silver medal here in the 100 breaststroke. Soni used a powerful final 50 meters to pull away from Australia's Leisel Jones, who won silver.

In the women's 100 freestyle, American Natalie Coughlin placed third for her fifth medal of the Games. Germany's Britta Steffen won gold.

U.S. women out of 800 free

Katie Hoff was supposed to start the final of the 800-meter freestyle at the Summer Olympics in one of the center lanes at the National Aquatics Center, swimming for her sixth medal. Kate Ziegler was supposed to be by her side, a two-time world champion in the event and a potential gold medalist.

But in one dramatic half-hour period Thursday night, the Beijing Games ended for Hoff and Ziegler. Each labored in her semifinal heat of the race. Each missed her personal best time by a wide margin. And each capped a disappointing meet here by failing to reach the final of a race in which either could have won gold.

"I don't think many people bet on that," Ziegler said shortly after emerging from the pool.

In an event in which the top eight move on to Saturday's final, Hoff was 11th-fastest Thursday, Ziegler 10th, neither within eight-and-a-half seconds of Britain's Rebecca Adlington, the pacesetter. The dual result left the Americans, who have won a medal in the women's 800 freestyle in every Olympics in which they have participated, without a representative in the final for the first time ever.

Hoff leaves her second Olympics with three medals — a silver and two bronzes.

The Washington Post contributed to this report.