Denis Pankratov can rest easy because Tom Malchow couldn't in the hours before the 200 butterfly today at the Pan Pacific swimming championships.

Malchow just missed the Russian's four-year-old world record in Tuesday's semifinal -- finishing in 1 minute 55.76 seconds, a half-second slower than Pankratov's 1995 mark of 1:55.22.

Thinking about breaking the record cut into Malchow's sleep time Tuesday night.

Today, the 23-year-old American lowered his time to 1:55.41 -- .19 off Pankratov's mark -- to win the event, even though he didn't get a good night's sleep.

"After my semi swim, a few people came up to me and talked a bit about the record," Malchow said after posting the second-fastest time in the history of the event. "I thought, `Wow, I could do this,' and tossed and turned a bit through the night.

"I don't know whether it made the difference -- I supposed it could have. But I've done the best three swims of my life."

Malchow, who is from St. Paul, Minn., but lives in Ann Arbor, Mich., finished almost two seconds clear of Japan's Takashi Yamamoto. American Ugur Tanner was third.

Malchow, the Olympic silver medalist behind Pankratov in Atlanta in 1996, says he'll probably ease off in his pursuit of the world record until the U.S. Olympic swim trials next August.

"It would be nice to give it a chase then," Malchow said. "I'm close enough to see that it can be done."

Australian teenager Ian Thorpe got his fourth world record in as many days when he led the men's 800-meter relay team to a stunning performance today. Thorpe, who also has broken two world records in the 200 freestyle and one in the 400, helped Australia beat its previous world mark by more than three seconds.