LONDON — 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.” Right after Phelps was done, 15-year-old Katie Ledecky — the youngest member of the US team — nearly broke the world record to win gold in the 800 freestyle, denying Britain's Rebecca Adlington a repeat before her home fans. Adlington settled for bronze in a race Ledecky dominated from start to finish, falling off record pace only in the last 15 meters. But no one has dominated like Phelps, who increased his career overall medal total to 21. “He's the king of the Olympics Games,” said his butterfly rival, Serbia's Milorad Cavic. Even though Phelps didn't go as fast in the final as he did in the semifinals, he actually won by a relatively comfortable margin compared to his two previous Olympic wins in the 100 fly — by four-hundredths of a second over Ian Crocker in 2004, then by one-hundredth of a second — the closest race possible — against Cavic at the Beijing Games four years ago. That was the victory that kept Phelps on course to win a historic eight gold medals in China. This was about going out in style. Phelps touched in 51.21 seconds to beat out the guy who edged him in the 200 fly, Chad le Clos. The South African touched in 51.44, tying for silver with Russia's Evgeny Korotyshkin. Cavic tied for fourth in 51.81, not even close to Phelps in their final meeting. France won its fourth gold at the pool, its best showing ever, as Florent Manaudou — younger brother of 2004 gold medalist Laure Manaudou — shocked defending Olympic champion and world-record holder Cesar Cielo of Brazil in the 50 freestyle. Manaudou touched in 21.34 and pounded the water out in Lane 7, then got a big hug from his sister as soon as he climbed from the pool. Cullen Jones of the United States took silver in 21.54, while Cielo was left with bronze in 21.59. Anthony Ervin, the 2000 Olympic champion who came back from an eight-year retirement, finished fifth after getting off to a poor start. — AP