Seventh at the turn, an Olympic champion at the end.

Make it 17 gold medals for Michael Phelps.

What a way to go out in the final individual race of his career.

With those long arms whipping through the water, Phelps was next-to-last when he touched the wall at the far end of the pool in the 100-meter butterfly, but in a familiar position when he made the touch that counted Friday -- his name atop the leaderboard, a smile on his face, another gold medal around his neck.

''I'm just happy that the last one was a win,'' Phelps said. ''That's all I really wanted coming into the night.''

He claimed his third gold of the London Games and 17th of his career, adding to an already absurd record total that should be twice as much as anyone else by the time he swims the final race of his career, the 4x100 medley relay Saturday night.

The Americans are huge favorites in a race they have never lost, and it's unfathomable to think the Phelps era could end with anything less than a performance that puts him atop the podium one last time.

In what might be viewed as a symbolic changing of the guard from America's greatest swimming star to the next big thing, 17-year-old Missy Franklin set a world record in the 200 backstroke, her third gold in London, just minutes before Phelps took center stage at the Olympic Aquatics Centre.

Another American teen, 19-year-old Elizabeth Beisel, claimed the 200 back bronze.

''I can't believe what just happened,'' said Franklin, who had dedicated her Olympics to victims of the theater shooting not far from her Colorado home.

''In that last 25, I knew I was giving it everything I had because I couldn't feel my arms and legs and I was just trying to get my hand to the wall as fast I could.''