"It's frustrating, that's all I can say. It's pretty upsetting," Phelps said. "The biggest thing now is to try to look forward. I have a bunch of other races, and hopefully we can finish a lot better than how we started."
China had a big night, claiming a couple of gold medals.
Sixteen-year-old Ye Shiwen set a world record in the women's 400 individual medley — only the third mark to fall since high-tech bodysuits were banned at the end of 2009. She won in 4:28.43, breaking the mark of 4:29.45 by Australia's Stephanie Rice at the 2008 Beijing Games. American Elizabeth Beisel took silver and China's Li Xuanxu grabbed the bronze.
Sun Yang flirted with a world record in the men's 400 freestyle. He took gold in 3:40.14, just off the mark of 3:40.07 by Germany's Paul Biedermann in a rubberized suit three years ago. When it was done, Sun propped himself on the lane rope, pumping his fist and splashing the water.
South Korea's Park Tae-hwan won silver in 3:42.06, fortunate even to take part after initially being disqualified for a false start in the prelims. The ruling was overturned by governing body FINA a couple of hours later on appeal. Peter Vanderkaay of the U.S. won the bronze.
Australia captured gold in the women's 400 freestyle relay with an Olympic record of 3:33.15, rallying to pass the Americans and hold off the fast-charging Netherlands.
The U.S. got off to a blistering start with Missy Franklin swimming leadoff under world-record pace, and the Americans were still ahead after Jessica Hardy went next. But the Australians rallied behind Brittany Elmslie on the third 100, and Melanie Schlanger held on at the end, with Ranomi Kromowidjojo closing fast to give the Netherlands a silver in 3:33.79.
The other members of the winning team were Alicia Coutts and Cate Campbell.
The Americans slipped to the bronze in 3:34.24, but that was still good enough to give Natalie Coughlin the 12th medal of her career, tying Dara Torres and Jenny Thompson as the most decorated U.S. female Olympians in any sport.
Coughlin swam in the morning prelims, then was reduced to the role of cheerleader in the evening as the Americans went with Franklin, Hardy, Lia Neal and Allison Schmitt. Everyone who swims on a relay gets a medal, though.
"I really have no idea what to think of it so far," Coughlin said. "I'll have to take it all in tonight. I'm very proud of it, but I've never been on a morning relay before."
There was no medal for Phelps.
His close call in the morning prelims put him in an already uncustomary position — swimming on the outside in the No. 8 lane. He only had one swimmer next to him and no idea what Lochte and the others in the middle of the pool were doing.
Not that it would have mattered.
"I don't think the lane had anything to do with it," Phelps said. "I just couldn't really put myself in a good spot for that race. It's frustrating for sure. ... It's just really frustrating to start off on a bad note like this."
Phelps still has six more events to swim in London, plenty of time to make up for his dismal start. He remains two behind the most medals won by any Olympian — Soviet gymnast Larisa Latynina's mark of 18 — nine gold, five silver, four bronze.
Phelps put himself in position to swim another eight events with his performance at the U.S. trials, but he decided to drop the 200-meter freestyle, feeling one less race would give his body a better chance to recover and improve his performance in the other events.
Now, he may be regretting that decision.
The 400 IM was an event he has dominated, winning gold at the last two Olympics and holding the world record for a full decade. But, tired of putting his body through such a grind, he dropped it from his program after setting a world record in Beijing four years ago (4:03.84), vowing never to swim it again.
He should have stuck with that pledge. Clearly, Phelps didn't leave himself enough time to get back in the kind of shape he needed to win the brutal race, having only brought it back earlier this year.