The moment of taking the crown.

There was no stopping Michael Phelps this time and Federica Pellegrini still can't be stopped.

Having failed to win his opening two events at the world championships, Phelps finally got gold in the 200 meters butterfly yesterday. In the next event, Italy's Pellegrini won the 200 freestyle to become the first woman to sweep the 200 and 400 at consecutive worlds.

This was Phelps' fifth world title in the 200 fly - and nobody else has more than two. He's also won the event at the last two Olympics. "That's sort of been my bread and butter event," Phelps said.

Australian great Ian Thorpe, who recorded the 200-400 double in 2001 and 2003, is the only other swimmer besides Pellegrini to achieve the sweep.

"You've just got to always believe in yourself. It's great to be a part of history," said Pellegrini, who is also the Olympic 200 champion. "This was my race, and nobody was going to enter my house."

In a non-Olympic race, Brazil's Felipe Silva beat Italy's Fabio Scozzoli in the 50 breaststroke, with defending champion Cameron van der Burgh of South Africa third.

Midway through the eight-day meet, no world records have been set - a sharp contrast from the 43 marks that fell at the last worlds in Rome two years ago, before high-tech bodysuits were banned.

Phelps let his lead slip on the final turn but then overtook Japan's Takeshi Matsuda early in the last lap to clock 1 minute, 53.34 seconds, hardly celebrating. Matsuda took the silver in 1:54.01 and Wu Peng of China got the bronze in 1:54.67.

Phelps led off the 4x100 relay when the United States took bronze on the opening night of the competition on Sunday, then settled for silver behind teammate Ryan Lochte in the 200 free on Tuesday.

A 14-time Olympic champion, Phelps now has a record 23 golds at worlds.

"I felt like myself the last 100 of that race. I didn't feel like I was dying," Phelps said. "I wanted to do what I usually do when I'm in better shape," Phelps added. "I wanted to step on it from the get-go. I saw the other swimmers at the 150 and I put my hips into it. I know there's a lot more I can do in that race."

Phelps had a streak of 60 consecutive wins in this event covering nearly nine years until he lost consecutive races to Wu at two minor meets in the United States earlier this year.

Pellegrini has also had a trying two years, following the death of her coach Alberto Castagnetti after the 2009 worlds in Rome. Still, she dominated the 400 on Sunday with a second-half burst of speed.

This time, Pellegrini methodically reeled in her rivals, moving steadily up from seventh after 50 meters to fifth at the halfway mark and third heading into the final lap to touch in 1:55.58.

Kylie Palmer of Australia won the silver in 1:56.04 and Camille Muffat of France took the bronze in 1:56.10.

Pellegrini celebrated by propping herself up on a lane rope, then raised her arms and stuck her tongue out before revealing a wide smile.

"We saw yesterday that there were a few opponents capable of competing well, but Federica did everything we planned," said the Italian's new coach, Frenchman Philippe Lucas.

James Magnussen, who led off Australia's victorious 400 free relay four days ago, was fastest in the 100 free semifinals in 47.90. American sprinter Nathan Adrian qualified second and William Meynard of France was third.

Competing in his first world meet, the 20-year-old Magnussen created a buzz with his sizzling opening split of 47.49 against Phelps in the relay. "I haven't gotten a lot of sleep over the last two days, my mind's just been ticking over, so to get that one out of the way and get another sub-48 is a big confidence booster," Magnussen said.

Phelps also qualified second behind Lochte in the 200 individual medley in the semifinal heat, setting up another duel between the Americans. "He's not going to give up and neither am I," Lochte said.