LONDON — Michael Phelps spent the day thinking about all the things he's doing for the final time at the pool. It turns out that included one last win over Ryan Lochte.

Phelps finally got a gold all his own at his final Olympics.

Adding to an already unprecedented medal collection, he claimed his first individual victory of the London Games and handed Lochte a double disappointment on his rival's final night in the pool Thursday.

Phelps set the tone right from the start with a dominating butterfly leg to become the first male swimmer to win the same individual event at three straight Olympics in the 200-meter individual medley. He claimed his 20th career medal — and 16th gold — in 1 minute, 54.27 seconds, just off his winning time in Beijing but still good enough for gold, ahead of Lochte.

"Going into every call room, I said it's my last semifinal or my last prelim," Phelps said, reflecting on a busy day that included a morning swim, then two more races in the evening. "We're kind of chalking up all the lasts of certain things.

"Once it's all over, it's going to really hit me emotionally. I know for my mom it's very emotional. I'm the last Phelps to come through. She's watched my sisters go through the sport and retire."

Lochte settled for silver in 1:54.90, having split with Phelps in their two head-to-head races in London. Hungary's Laszlo Cseh took the bronze, well behind the Americans in 1:56.22.

"Ryan and I have had a lot of great races," Phelps said. "He has brought the best out of me many times."

Lochte's final London tally: two golds, two silvers, one bronze and a fourth-place finish — impressive, but undoubtedly shy of what he had predicted would be "my time."

Rebecca Soni made quite a splash, too, on a night dominated by the Phelps-Lochte showdown.

Tearing through the water in her favorite pink suit, Soni set her second world record in as many days to defend her Olympic title in the 200 breaststroke. She finished in 2:19.59, breaking her own mark of 2:20.00 set in the semifinals.

Soni broke into a big smile when she saw the time, racing the clock more than she was anyone in the water. Japan's Satomi Suzuki took silver, more than a second behind at 2:20.72, while Russia's Yulia Efimova claimed bronze in 2:20.92.

"I'm so happy," Soni said. "I can't believe I did it."

Tyler Clary rallied on the final lap to pull off the upset in the 200 backstroke in an Olympic-record 1:53.41. Japan's Ryosuke Irie also got by Lochte on the final stroke, taking silver in 1:53.78. Lochte's time was 1:53.94.

"You always have big dreams in your head that you think you might be able to pull off something like that," Clary said. "The fact that it just came to fruition is something that hasn't even processed in my mind yet. The fact that I'm now an Olympic champion and Olympic-record holder is something that is very humbling. It's also very motivating for the next four years."