Ryan Lochte tried to pull off a daunting double, going against Phelps just 29 minutes after swimming the final of the 200 backstroke. He couldn't keep up, though he did hold on for bronze. Laszlo Cseh of Hungary picked up his third silver of the games - all of them trailing Phelps.
Phelps hung on the lane rope in a familiar pose, admiring his time while his rivals gasped for breath. He extended his right hand to Lochte in the next lane, and the two friends shook hands and patted each other on the head.
Lochte got quite a consolation price: a world record and the first individual gold medal of his career in the backstroke. The laid-back Floridian edged teammate Aaron Peirsol in 1:53.94 to break the mark he shared with Peirsol.
Lochte was known as "Mr. Runner-up" for his frequent second-place finishes to Phelps and Peirsol. Then, he stunned Peirsol at last year's world championships in 1:54.32 and Peirsol matched the time in beating Lochte at the U.S. Olympic trials last month.
Peirsol won the 100 back in Beijing, but failed to match his backstroke double from Athens four years ago. He earned the silver in 1:54.33, while Russia's Arkady Vyatchanin claimed the bronze.
Phelps is just one gold away from tying Spitz's record of seven gold medals at the 1972 Munich Olympics. The 23-year-old from Baltimore was scheduled to return for the semifinals of the 100 butterfly about a half-hour after his win in the 200 IM; assuming he advances, he will try to equal the grandest of Olympic standards on Saturday morning.
If all goes according to plan, the record-breaker would come on Sunday's final day of swimming in the 400 medley relay. The Americans will be heavily favored for gold in that one.
Rebecca Soni gave the U.S. women's swim team a much-needed boost, setting a world record in the 200 breaststroke with an upset of Australia's Leisel Jones.
Soni had already claimed a surprising silver behind Jones in the 100 breast, a race she wasn't even supposed to be in. She took over when Jessica Hardy failed a doping test at the U.S. trials and was dropped from the team.
Jones was out front over the first 100, but Soni came on strong at the end, finishing a full body length ahead of the Aussie in 2:20.22. She beat Jones' mark of 2:20.54, set two 2½ years ago in Melbourne.
Jones claimed silver and Norway's Sara Nordenstam took bronze. Soni's victory came about 14 hours after American distance hopes Katie Hoff and Kate Ziegler failed to make the final of the 800 freestyle.
Lochte's win was the 20th world record set in swimming during the Olympics, with two days still to go.