The 19-year-old from Baltimore claimed his second and third gold medals of the Athens Games Tuesday night.
Phelps won the 200-meter butterfly race, though he was a bit disappointed at failing to break his own world record. He was also on the winning 800-meter freestyle relay team.
Phelps held off Takashi Yamamoto to win the butterfly race in an Olympic-record 1 minute, 54.01 seconds. The hard-charging Japanese swimmer took silver (1:54.56), while Great Britain's Stephen Parry won bronze (1:55.22).
With three gold and two bronze medals on the fourth day of the Olympic meet, Phelps is easily the most decorated swimmer. He had hoped to challenge Spitz's record of seven gold medals at the 1972 Munich Games, but that effort ended with third-place finishes in the 400 freestyle relay and 200 free.
Phelps went out strong in the fly - one of his best events - and reached the midway point under his world-record pace. He tired a bit at the end, falling short of the 1:53.93 that he set at last year's world championships.
Phelps turned quickly to look at the scoreboard, giving a timid fist pump when he saw his winning time.
"The third 50 was something that could have been better," he said. "I'm happy for the gold medal, but I really wanted the record."
Klete Keller narrowly held off Ian Thorpe at the wall to help the United States win gold over the Australians in the 800-meter freestyle relay Tuesday night.
The Americans won in 7 minutes, 7.33 seconds - a U.S. record - four years after finishing second to the Aussies at the Sydney Games.
The Australian team of Grant Hackett, Michael Klim, Nicholas Sprenger and Thorpe earned silver in 7:07.46. The Italian team of Emiliano Brembilla, Massimiliano Rosolino, Simone Cercato and Filippo Magnini took bronze in 7:11.83.
Phelps led off and had the Americans in front after 200 meters, with Hackett in second. The Aussies dropped to third behind the Americans and Italians on Klim's leg, but Sprenger moved them back to second before Thorpe took over.
Ryan Lochte and Peter Vanderkaay kept the U.S. lead, allowing Keller to dive in ahead of Thorpe on the anchor leg. Even though Thorpe's 200 split of 1:44.18 was faster than Keller's 1:45.53, the American was able to hold him off.
Phelps didn't have to swim in the morning for the first time, sitting out the preliminaries of the relay.
"I got to sleep in today, so I got a little bit of rest," he said. "I'll put all my energy into the relay."
The Americans picked up another medal when Amanda Beard took silver in the 200 individual medley. The three-time Olympian picked up the fifth medal of her career behind Ukraine's Yana Klochkova, who defended the title she won in Sydney with a time of 2:11.14.
Beard made a dramatic move during the breaststroke phase of the relay and finished in 2:11.70. Kirsty Coventry of Zimbabwe earned her second medal of the games, a bronze in 2:12.72.
Phelps' quest for seven gold medals ended after just three events, when he had to settle for another bronze Monday night in the most anticipated race at the Olympic pool — the head-to-head showdown with Australia's Ian Thorpe in the 200-meter freestyle.
Thorpe has ruled this event for years, but Phelps couldn't resist seeing what he could do against him — part of his larger goal to break Mark Spitz's record of seven golds at the 1972 Munich Games - a goal that gathered much attention in the weeks before the Games.
"I guess you could say a lot of the pressure is off," Phelps said.
"He came in here looking to get one gold, and he accomplished that," Phelps' sister, Whitney, told CBS News Early Show Co-Anchor Hannah Storm. Phelps won the 400 meter individual medley earlier.
"If you could have seen his face the night he won the 400 IM, he was smiling from ear-to-ear," his mother Debbie said.
"I think now he's just really, really enjoying what he's doing," Phelps' sister, Hilary, added. "He's just loving the competition."
Defending Olympic champion Pieter van den Hoogenband of the Netherlands won the silver.
Natalie Coughlin, the top female swimmer on the American team, won the 100 backstroke, holding off Kirsty Coventry of Zimbabwe. France's Laure Manaudou took bronze, her second medal of the games.
Aaron Peirsol was first in the men's 100 back. Markus Rogan of Austria claimed silver and Japan's Tomomi Morita held off American Lenny Krayzelburg for the bronze.
Luo Xuejuan of China won gold in the women's 100 breaststroke, beating Australians Brooke Hanson and Leisel Jones.
In other Olympic events:
The American men's gymnastics team, long overlooked and often unappreciated, won the Olympic silver to take home a medal for the first time since the boycotted 1984 Games.
After faltering in the middle two rotations, Paul and Morgan Hamm led a rally. The Americans hit their last six routines, on parallel bars and high bar, to push past Romania and finish with 172.933 points.
The Japanese went last and needed to average about 9.5 over three sets on the high bar to win. They did it with ease, winning by 0.888 points.
This was only the third team medal for the U.S. men, and their first at a non-boycotted Olympics since 1932.
Venus Williams and Chanda Rubin lost 7-5, 1-6, 6-3 to eighth-seeded Li Ting and Sun Tian Tian of China in the first round of the Olympic doubles tournament.
Williams won the doubles gold medal at the 2000 Sydney Games with her sister, Serena, who pulled out of these Olympics last week, citing a left knee injury. Rubin filled in, marking the first time Venus Williams ever played a tournament doubles match with anyone but her sibling.
In men's doubles, the top-seeded Bryan twins, Bob and Mike, routed Russians Marat Safin and Mikhail Youzhny 6-1, 6-2.
In singles play Roger Federer of Switzerland, the top-ranked player in the world, struggled but rallied to beat Russia Nikolay Davydenko 6-3, 5-7, 6-1.
The U.S. women's team overcame another slow start and beat the Czech Republic. With key contributions from Tina Thompson and reserve Yolanda Griffith, the Americans went on a 14-point spurt to take the lead for good, then blew the game open with a 16-2 run at the start of the second half.
Lisa Leslie led the United States with 15 points, Thompson scored 12 and Griffith had 10. Quicker than their taller opponents, the United States outrebounded the Czechs 43-22.
Earlier, Ryoko Yano had 21 points and Mutsuko Nagata added 20 to help Japan rebound from an opening loss.
Donna Loffhagen had 19 points and 14 rebounds, and New Zealand bounced back from a 52-point, opening-game loss to the United States.
Spanish forward Madariaga Valdemoro scored 30 points against China as her team clinched a spot in the quarterfinals.
Two days after setting an Olympic record for points and matching the mark for margin of victory in a 128-62 win over Japan, Brazil was tied 64-64 with Greece after three quarters. Brazil opened the final quarter with a 14-0 run to take control and silence a frenzied home crowd of 2,200.
Lori Harrigan allowed only a first-inning bunt single and Crystl Bustos homered as the Americans posted their fourth straight shutout of the games.
Harrigan struck out eight as the United States (4-0) coasted past another of the tournament's medal contenders.
Lovieanne Jung had two RBIs and Leah O'Brien-Amico drove in a run as the Americans ran their winning streak to 74 games.
Zhu Qinan of China set a world record, winning the gold medal in 10-meter men's air rifle.
Zhu scored 702.7, topping the mark of 702.5 set by American Jason Parker in 2003. China's Li Jie took the silver and Slovakia's Jozef Gonci won the bronze.
Suzanne Balogh of Australia pulled away from the field to win the gold medal in trap shooting. Maria Quintanal of Spain took the silver. American Collyn Loper, of Indian Springs, Ala., finished fourth, one point behind Lee Bo-na of South Korea, who won the bronze.
Water Polo - Men
Francesco Postiglione scored three goals Tuesday as Italy rebounded from an opening loss to Spain.
The Australians led twice in the first two periods and were tied 3-all at the break, but Italy scored three consecutive in the third period and took control.
Germany led 9-0 at halftime and added two goals in the third period before Egypt scored.
Brenda Villa scored four goals and Kelly Rulon had a pair as the world champion United States began the pursuit for an Olympic gold medal with a win over Hungary.
The Americans led by three goals after the first quarter, but the Hungarians rallied to 5-5 late in the third quarter and took a 6-5 lead in the final period.
Villa pulled the United States to 6-6. Then Rulon — celebrating her Olympic debut and her 20th birthday — scored the winning goal a minute later.
In the other Group B match, Russian captain Sofya Konukh scored three goals and Maria Yaina scored twice. Susan Gardner had two goals for Canada.
In Group A, Olympic champion Australia edged No. 2-ranked Italy, with Kelly Heuchan and Kate Gynther contributing two goals apiece. Greece defeated Kazakhstan.
Forecasts of strong winds prompted organizers to postpone Monday's races — organizers hoped to move them to Tuesday.
The strong Meltemi wind that led to the cancellation of rowing also claimed the 49er event in sailing after sailors weren't able to get their boats in the water.
The wind didn't help Kevin Hall of Bowie, Md., who finished 16th and 14th in the two Finn races to drop to 14th overall.
He was buried in 19th at the first mark of the first race because he was unable to gain from a wind shift.
Monday's wind averaged 21 knots, gusting higher at times, although the swell was down from Sunday, when at least 30 boats capsized on the wild Saronic Gulf.
While the conditions had the Finns flying across the waves, the anticipated first three races of the 49er class were postponed because of the stiff breeze that kept the flags at the Agios Kosmas Sailing Center whipping toward the gulf.
France's Brice Guyart rallied from an early deficit in the final to defeat Italy's Salvatore Sanzo and win the gold medal in men's foil. Guyart trailed 4-0 but quickly tied the bout and won 15-13. Andrea Cassara of Italy defeated Russia's Renal Ganeev 15-12 to take the bronze.
Dan Kellner, of Warren, N.J., fell one touch short of reaching the quarterfinals. He upset No. 7 seed Cedric Gohy of 15-12 in the round of 32, and led 14-12 in his next bout but couldn't close out the win, as Britain's Richard Kruse rallied to win 15-14.
World champion Lee Won-hee of South Korea defeated American Jimmy Pedro in the third round and went on to claim the gold medal in the 73kg class, beating Vitaliy Makarov of Russia in the final.
Pedro bounced back for a bronze, which he shared with Leandro Guilheiro of Brazil.
Lee and Pedro had been the focus of the competition ever since the draw was announced.
Pedro, a 1996 bronze medalist and four-time Olympian, ended Lee's 48-match winning streak last December. Pedro (Lawrence, Mass.) retired after the Sydney Olympics before making a comeback.
After losing to Lee, Pedro had to fight his way through the repechage bracket to win the bronze medal.
In the women's 57kg final, Yvonne Boenisch of Germany beat North Korea's Kye Sun Hui, the two-time world champion. Deborah Gravenstijn of the Netherlands and Yurieleidys Lupetey of Cuba shared the bronze.
Nikolaos Siranidis and Thomas Bimis of Greece won the gold medal in synchronized 3-meter springboard diving with a score of 353.34. It was Greece's first gold at the Athens Games.
Andreas Wels and Tobias Schellenberg of Germany won the silver medal. Robert Newbery and Steven Barnett of Australia got the bronze.
Lao Lishi and Li Ting earned China its third diving gold medal in these Olympics by easily winning the women's 10-meter synchronized platform competition.
Natalia Goncharova and Yulia Koltunova of Russia won the silver and Blythe Hartley and Emilie Heymans of Canada took the bronze at 327.78.
China swept the gold medals in two events and finished 1-2 at men's 137 pounds (62kg).
Shi Zhiyong, not deterred by either the pro-Greece crowd or his own teammate, held off countryman Le Maosheng and Greece's Leonidas Sampanis to win the 137-pound gold. Le won the silver and Sampanis, a silver medalist in the last two Olympics, was happy to get the bronze at age 32. His was Greece's first medal of its homeland Olympics.
Earlier, Chen Yanqing won gold at 127 pounds (58 kg), her first major title since winning the 1999 world championship in Athens. North Korea's Ri Song Hui took the silver and Wandee Kameaim won the bronze, Thailand's second weightlifting medal in as many days.
Defending Olympic champion Simon Fairweather of Australia was knocked out by Anton Prylepav of Belarus in the first men's elimination round at Panathinaiko Stadium. Fairweather, seeded 20th, lost 141-137. Australia's David Barnes was also eliminated.
Vic Wunderle of Mason City, Ill., who won a silver in individual and bronze in the team competition in Sydney, was the only American to advance. Butch Johnson (Worcester, Mass.) and John Magera (Carterville, Ill.) lost.
Bhutan's Tashi Peljor pulled the biggest upset of the day, beating 13th seed Jocelyn de Grandis of France. Archery is the national sport of Bhutan.