Fitting finale: Michael Phelps retires with one last gold

Michael Phelps got up to leave his last news conference at the Olympic pool when his relay mates were asked if they thought he would really stay retired.

Before they could answer, Phelps smiled and said emphatically: "Yes, yes."

The most decorated Olympian called it a career on Saturday night with a fitting ending — a gold medal in the 4x100-meter medley relay at the London Games.

- London Olympics 2012 - Complete coverage

Phelps's total in four Olympics: 22 medals, 18 golds, 51 races and 9,900 metres of swimming.

"I've been able to do everything that I wanted," he said. "If you can say that about your career, there's no need to move forward. Time for other things."

Having hung up his suit, cap and goggles for the last time, the 27-year-old from Baltimore is looking forward to the rest of his life.

He wants to travel and see places beyond the pools and hotel rooms of the last 12 years. His intended destinations include Australia and Europe. He wants to go cage diving among great white sharks in South Africa with Chad le Clos, the last man to beat him in the Olympics.

"I've been able to see so many amazing places in the world, but I've really never gotten to experience them," Phelps said.

"He needs time for himself first," his mother Debbie said.

Phelps still plans to be around the sport that made him rich and famous, saying, "I would like to try to take it to an even higher level than it is now."

He certainly left it on a high note.

Phelps regained the lead in the medley relay with his trademark butterfly stroke, then handed it over to freestyle anchor Nathan Adrian.

Adrian brought it home in 3 minutes, 29.35 seconds. Japan took the silver in 3:31.26 and Australia got the bronze in 3:31.68. The team of Matt Grevers, Brendan Hansen, Phelps and Adrian hugged before Phelps waved and smiled to the crowd.

Later, he grew reflective, saying, "I'm a lot more relaxed than I thought I'd be in this moment."

Warming up before his last race, Phelps called his coach over to the side of the practice pool. He thanked Bob Bowman for helping him win all those medals, a feat they accomplished together.

That private moment got to both of them.

"I said, 'My tears could hide behind my goggles. Yours are streaming down your face,'" Phelps said. "I wouldn't be here today without everything he's done for me. I love him to death."

Bowman said: "I'll never forget that as long as I live."

On a night when Phelps exited the world stage, Missy Franklin capped a brilliant Olympic debut by helping the U.S. win gold in the women's medley relay in a world-record time.

The 17-year-old high school student gives the U.S. hope for the post-Phelps era, having won five medals in London, including four golds to match Amy Van Dyken at the 1996 Atlanta Games for the most by an American female swimmer. She swam seven events, the same as Phelps.

"I don't think his shoes will ever be filled. They're so huge," Franklin said. "Hopefully I can make little paths next to him."

The Americans dominated the medal count at the pool, finishing with 16 golds and 30 overall.