ROME — Michael Phelps had every reason to be satisfied after the Beijing Olympics. Yet he kept insisting there was more to do in the pool.

Clearly.

Even coming off his longest layoff and the embarrassment of being photographed inhaling from a marijuana pipe, Phelps turned in another remarkable performance over eight days at the Foro Italico. He completed it Sunday night by helping the U.S. 400-meter medley relay team set the 43rd world record of the fastest meet in history.

OK, he didn't win another eight golds. This time, he made do with five golds and a silver.

Still, Phelps showed plenty of fire, even when there's really nothing left to prove.

"I never want to look back on career and ask, 'What if?'" he said.

Swimming the butterfly leg, Phelps helped the U.S. pull away from Germany and Australia to win in 3 minutes, 27.28 seconds. That easily broke the mark of 3:29.34 set by the Americans at last summer's Olympics, another relay team that included Phelps.

"That relay brings out the best in me," Phelps said. "It doesn't matter how much energy I have, it's all going to go into every race. That's one of the things that I enjoy most — stepping out onto the blocks no matter what kind of shape I'm in."

Phelps took six months off after his Beijing triumph, drew a three-month suspension from competition after the infamous pipe photo — and he was still honored as the outstanding male swimmer of the championships. Italy's Federica Pellegrini received the female award at the final major meet for high-tech bodysuits, which will be banned Jan. 1.

We aren't likely to see these sort of times for years, maybe decades.

But Phelps said he's not concerned about turning back to the clock on attire. He's got plenty of goals in mind.

"I have more things I want to do," he said. "That's why I wanted to come back. I don't care if anyone says it was a bad idea or not, it's something that I wanted and that's why I'm doing it."

His coach, Bob Bowman, said Phelps will get all of two weeks off before he's back in the pool.

On to London in 2012.

"I've got to be in better shape," Phelps said. "I think without taking six months off, that will do it."

When he had the final gold of the world championships in his possession, Phelps made his usual climb into the stands to get a hug from his mother and sister.

It was Debbie Phelps who got her son fired up for Rome by saying she wanted to see him swim in the Eternal City, not just get in a little sightseeing.

"I didn't want her to come here and not swim well in front of her," he said.

He found other reasons to be motivated — notably when Serbia's Milorad Cavic tried to get in his head before their showdown in the 100 fly. Both swimmers became the first to break 50 seconds, but it was Phelps who touched first in a world record.

"A lot of motivating comments were said," Phelps pointed out, without mentioning Cavic by name. "That always gets me going. That's something that helped me along the way."

Eric Shanteau, who overcame testicular cancer to swim his best times, picked up the first major gold medal of his career on the breaststroke leg of the relay, to go along with a silver and a bronze in Rome. The other members of the winning team were backstroker Aaron Peirsol and freestyle anchor David Walters.

Shanteau was thrilled to finally step on the top rung of the podium. Last summer, he learned just before the U.S. Olympic trials he had cancer. He put off treatment until after the games, underwent surgery when he got home and has been cancer-free since.

"What a great way to end it," said Shanteau, who had missed an individual gold by one-hundredth of a second in the 200 breaststroke. "To finally get it, that gold medal, was an unbelievable feeling."

Also Sunday, Ryan Lochte won his fourth gold of the championships and Germany's Britta Steffen matched her 50-100 freestyle sweep in Beijing.

No such glory for 42-year-old Dara Torres. The senior citizen of the pool finished last in her only individual final at the Foro Italico.

"I like to win, but eighth fastest in the world at 42, so I can't be too disappointed," she said.

Torres failed to match her silver-medal showing from the Olympics, when she finished just one-hundredth of a second behind Steffen. Bothered by a sore knee that will require surgery, the American was eighth in 24.48.

She plans to return to the pool in December and hasn't ruled out anything, even trying for the London Olympics at 45.

Lochte, taking advantage of Phelps' absence, added the 400 individual medley title to his medal haul at the championships. Lochte also won the 200 IM along with two relay golds, in addition to taking bronze in the 200 backstroke.

Lochte was far off Phelps' world record in the 400 IM, touching first in 4:07.01. Phelps won gold at Beijing in 4:03.84, but decided to scale back his program heading into what will be his final Olympics.

"It definitely felt good to get these wins after coming second to Michael for so long," said Lochte, who broke Phelps' world record in the 200 IM with his rival cheering from the stands. "But I wish he was here swimming just because he's a great competitor and I love racing him. I'm trying to talk him into doing the IM again."

The Americans still went 1-2 even without Phelps. Tyler Clary came on strong in the freestyle to beat Hungary's Laszlo Cseh, taking silver in 4:07.31. Cseh settled for bronze at 4:07.37.

Both were closing fast when Lochte touched.

"I didn't think it was going to hurt that much," the winner said. "When I touched going into the freestyle, I just had a body-length lead and I just thought, 'If this hurts too bad, I'll lose it.' Then, you know, I just gave it everything I had. That's all I could ask for it."

The win gave Lochte another chance to break out his diamond-studded "grillz," which he popped in his mouth while posing for photographers after the medal ceremony.

Steffen was one of the biggest female stars in Rome. She set her third world record of the meet while winning the 50 free in 23.73.

The German repeated her Olympic feat in a blistering race, beating the mark of 23.96 held by Marleen Veldhuis of the Netherlands since April. Sweden's Therese Alshammar went under the old record as well, settling for silver (23.88). Australian teenager Cate Campbell got bronze.

Tunisia's Ous Mellouli matched his Olympic gold by winning again in the 1,500 free, the longest event in the pool. After a tight battle over the first 1,000 meters with Canada's Ryan Cochrane, Mellouli pulled away to win in 14:37.28, though short of Grant Hackett's 8-year-old world record of 14:34.56.

Another race where the old mark stood up was the women's 400 IM, won by Hungary's Katinka Hosszu in 14:30.31, just off Stephanie Rice's mark of 4:29.45 at last summer's Olympics. Kirsty Coventry of Zimbabwe got the silver and Rice, one of the biggest stars in Beijing but not quite on form in Rome, held on for bronze.

A pair of world records fell in non-Olympic events.

Liam Tancock broke his own world record to win the 50 backstroke. The British swimmer touched in 24.04, eclipsing the mark of 24.08 he set the previous day in the semifinals. Japan's Junya Koga claimed silver and South Africa's Gerhard Zandberg earned bronze.

Russia's Yuliya Efimova set a world record while edging American Rebecca Soni in the 50 breaststroke. Efimova won in 30.09, breaking the record of 30.23 set by Canada's Amanda Reason less than a month ago. The next two also went under the old mark, with Soni (30.11) taking silver and Australia's Sarah Katsoulis (30.16) the bronze.

Phelps set two individual world records and was on two relay teams that broke marks.

He doesn't mind seem to mind that it'll be tougher to approach these times under the stricter swimsuit rules.

"This is about a sport and the athletes in it," Phelps said. "That's what makes it interesting. It doesn't matter what suit you're wearing."