"I've said this before - this is my year," Lochte exulted.
"Frustrating," Phelps said. "It was pretty upsetting. But the biggest thing now is trying to get past this and move forward."
Brazil's Thiago Pereira and Japan's Kosuke Hagino separated Lochte and Phelps by finishing second and third, respectively. Phelps' world record of 4 minutes, 3.84 seconds set in a high-tech swimsuit in the 2008 Olympics was not seriously threatened by Lochte (4:05.18), but Phelps was nearly six seconds off his pace from 2008. Lochte led almost wire-to-wire, winning by more than three seconds in what is generally considered swimming's most grueling race.
Phelps called it "a crappy race" afterward while Lochte alternated between celebration and surprise. "When I touched the wall, I guess I was in shock," he said. "I think I still am - that I finally won."
As for not having Phelps with him on the medal stand, Lochte said: "Tell you what, it's weird."
And it was weird. Phelps had medaled in his previous 16 Olympic events, with 14 golds and two bronzes. He won six golds in eight events in the 2004 Olympics, then gave one of the most dynamic performances in Olympic history in China when he went 8 for 8 on gold medals. He remains two short of the all-time record for overall medals.
But Phelps has been getting beaten with some regularity in various events this season, sometimes in his signature butterfly stroke. Lochte had beaten him in the 400 IM at the U.S. Olympic trials (where Phelps was faster than he was Saturday) and has defeated him enough that it is commonly accepted in the swim world that Lochte has been a better swimmer than Phelps since Beijing.
Still, the Olympics is usually where Phelps puts everything together. He had won the 400 IM in each of the last two Olympics and was trying to become the first male swimmer to win the same individual event at three straight.
Phelps, 27, plans to make these his final Olympics while Lochte, who is about 11 months older and will turn 28 during these Olympics, plans to continue swimming through at least 2016. Phelps had talked earlier in the week about bringing his career to closure with several more fine performances in London.
Phelps didn't mention Lochte in his brief interview following the event, but later congratulated his teammate, according to Lochte.
"He was definitely proud of me," Lochte said. "I know at the same time he was kind of upset."
Phelps and Lochte each have as many as six more races at these Olympics, depending on which relays they swim. They will face off one more time, in the 200 individual medley.
Phelps also looked vulnerable in the race's morning preliminaries. He finished eighth-fastest - sliding into the last spot in the eight-man final - in a morning that hinted at the fourth-place finish to come.
"A lot of people say Michael is inhuman," Lochte said. "But you know what? He's just like all of us."
Lochte has been telling himself that for years. In Beijing, it wasn't true.
In London, it finally is.