COLUMBIA, Mo. — Katie Hoff set her second American record in as many days today when she and six-time Olympic gold medalist Michael Phelps each cruised to a pair of victories at the Missouri Grand Prix.

Both easily won their respective 200-meter freestyle and 400 individual medley races on the second day of the meet.

Hoff set an American record in the 200, finishing in 1 minute, 56.08 seconds to defeat five-time Olympic medalist Natalie Coughlin for the second time in two days. Coughlin set the previous mark.

On Saturday, Hoff broke the oldest American record on the books in the 400 freestyle.

In Sunday's medley, Hoff beat Kirsty Coventry of Zimbabwe, who a day earlier set a world record in the 200 backstroke.

The 18-year-old Hoff, the youngest U.S. Olympian four years ago, seems reluctant to embrace the role of America's top overall female swimmer heading toward the Beijing Olympics in six months.

"Everyone has something to bring," she said, naming several other top female swimmers. "I'm just excited to be confident going into the next five or six months of training and getting ready for (Olympic) trials."

With two events remaining on the final day of the Grand Prix on Monday, Hoff has won four races here.

Phelps, who also won the only event he entered Saturday, was disappointed with his time of 4 minutes, 14.08 seconds in the medley Sunday. While second-place finisher Thiago Pereira was more than four seconds back, Phelps' time was nearly eight seconds off his personal best, which is a world record.

"I'm not happy about the 400 IM and where it is right now," he said. "I just have to get back into swimming back-to-back events, and being able to swim them well."

Phelps, the undisputed face of American swimming and a contender to break Mark Spitz's record of seven gold medals in a single Olympics, said he isn't surprised by the ascension of Hoff, his former teammate at the North Baltimore Aquatic Club.

"Our club team has always had a tradition for excellence," said Phelps, who now lives and trains in Ann Arbor, Mich. "I have no idea what they put in the water (there), but obviously it's something good."

Joining Phelps and Hoff as multiple winners at the meet was Cesar Cielo of Brazil, who won the 50 freestyle in 22.01 seconds. Fred Bousquet finished second, 0.04 seconds behind.

Cielo, who trains in Atlanta and swam at Auburn, won the 100-meter freestyle Saturday.