COLLEGE PARK, Maryland, 10 August 2003 — Michael Phelps smashed an American record for the second time in as many days, winning the 400-meter freestyle in 3 mins 46.73 secs here on Friday at the United States Swim Championships.

Despite the effort of 21 races in two weeks, including five world records at July’s World Championships in Barcelona, the 18-year-old from nearby Baltimore broke the old US mark of 3:47.00 set by Klete Keller at the 2000 Olympics.

“That last 150 was extremely painful,” Phelps said. “I’m starting to feel worlds. Everything is starting to catch up to me. The last 150 I owe to the crowd. They pretty much got me through.”

In an event he seldom swims, Phelps became the eighth-fastest performer in history, although shy of Australian Ian Thorpe’s world record of 3:40.08 from last year’s Commonwealth Games in Manchester, England.

“With all that has been going on, I’m extremely pleased,” Phelps said.

Phelps won world crowns in the 200 butterfly and 200 and 400 individual medley in Spain. The new world swim king is testing himself in events beyond his specialties here as training for the Athens Olympics next August.

Phelps won his fourth title of this meet after taking the 200 backstroke and 100 freestyle Wednesday and lowered his own US mark in the 200 free Thursday. But he is pushing the limits of exhaustion.

The US meet concludes Saturday with Phelps swimming in the 400 medley relay and the 200 individual medley. Phelps does not expect to approach his world record of 1:56.04 from Barcelona.

Phelps will decide in a month the events he wants to swim at Athens but wants to swim on all US freestyle relays as part of his ultimate goal, matching the Olympic record of seven gold medals won by Mark Spitz in 1972 at Munich.

US Olympic men’s swim coach Eddie Reese praised Phelps, saying he likely can make the US squad in his weakest events, if he has any weak ones.

“The last guy I saw like him was Mark Spitz, just such a gift,” Reese said. “The other swimmers line up to watch him. The last time you saw that was Spitz.

Reigning Olympic champion Megan Quann won the women’s 100 breaststroke in 1:08.80 while Olympic silver medalist Ed Moses won the men’s crown in 1:01.11.

South Africa’s Eugene Botes won the 100 butterfly in 53.20 seconds. Non-US swimmers compete here for US clubs. Botes swims at Penn State University.

Jeff Rouse, the 1992 Olympic 100 backstroke runner-up and 1996 Olympic champion back at age 33 after a six-year retirement, was second in the event in a personal best 55.64, 1.01 behind winner Randall Bal.