Germany's Paul Biedermann reacts after smashing Michael Phelps's world record in the men's 200-metre freestyle event Tuesday in Rome. ((Pier Paolo Cito/Associated Press))

German Paul Biedermann has ended Michael Phelps's domination of the men's 200-metre freestyle, smashing the American's world record on Tuesday en route to a gold medal at the World Aquatics Championships in Rome.

Biedermann raced to a time of 1 minute, 42 seconds, eclipsing the mark of 1:42.96 the American set at last year's Beijing Olympics.

Phelps finished a full body length behind the German in 1:43.22. Russia's Danila Izotov took the bronze in 1:43.90.

It was the Baltimore native's first major international defeat since losing to compatriot Ian Crocker in the 100 butterfly during the 2005 world championships in Montreal.

It's the second gold medal of the competition for Biedermann, who also broke a world record in the 400 freestyle on Sunday to erase Australian great Ian Thorpe's mark.

Phelps grabbed the lead off the the blocks, but Biedermann surged ahead by the opening flip. After the final turn, the German had built up an insurmountable lead.

"For the moment it is just like a dream. It's such an amazing feeling. I'm so fine," he told reporters after the race.

Only 22, Biedermann didn't think defeating the 2005 and 2007 world champion would come so quickly.

"Maybe in two or three years, not now," he said.

Phelps is coming off a long layoff that included a three-month suspension resulting from a photo fallout showing the Olympic great inhaling from a marijuana pipe.

"Theoretically that was a pretty good swim for me," said Phelps, who conceded to CBC Sports swimming analyst Byron MacDonald in June that he gained 20 pounds. "Three-tenths off my best time after taking sixth months off. I'm not happy but I know I didn't train much this year."

Biedermann's victory does come with one caveat: The German was using a high-tech bodysuit that swimming's governing body FINA upheld a decision on Tuesday to ban next year. However, the decision to outlaw the suit may not take effect until April or May of 2010.

Biedermann sports an Arena X-Glide, a polyurethane suit considered significantly faster than Speedo's LZR Racer — the suit Phelps wears.

Suit a major factor

An Italian manufacturing company designed the Arena X-Glide, which is made completely out of a rubberized material.

Biedermann admitted the suit made him at least one second faster.

"The suits make a difference," Biedermann said. "Last year, it was Speedo. This year, it's Arena.

"I hope there will be a time when I can beat Michael Phelps without these suits," the German added. "I hope next year. I hope it's really soon."

In the men's 100 backstroke, Japan's Junya Koga took home the gold in 52.26 seconds. Koga's victory was made easier after American Aaron Peirsol was shockingly eliminated in Monday's semifinal heat. Peirsol has won the last three world titles, two Olympic gold medals, and is also the world-record holder in this event. 

Cameron van der Burgh broke a world record in the men's 50 backstroke during the semifinal heat.  The South African bettered Felipe Da Silva's mark that the Brazilian set in early May.

With files from The Associated Press