BEIJING - There's no such thing as a day off when you're chasing history.
For Michael Phelps, this is as close as it gets.
Phelps is a perfect 5-for-5 in his quest to win a record eight medals, picking up two on Wednesday with a pair of world-record swims. He'll still be in the pool today, but there will be no medals on the line.
He had three races on Wednesday, also swimming a preliminary heat in the 200-meter individual medley in what was a long day for the star of these games.
'I'm just trying to get through everything,' he said. 'It's a lot of racing and it's not easy.'
He gets a breather today. His only events are semifinal heats in the 200 IM and 100-meter butterfly.
He earned it after his showing Wednesday made him the winningest Olympic athlete ever with his 10th and 11th career gold medals. He also has five world records in five events at the Beijing Games.
Phelps won the 200-meter butterfly in the morning, and followed it an hour later by swimming leadoff in a runaway victory by the U.S. 800 freestyle relay team. The group shattered the old world mark by more than four seconds as the Americans became the first team ever to break the 7-minute barrier.
'He is just another person, but maybe from a different planet,' said Alexander Sukhorukov, who swam the anchor leg for the second-place Russians.
Phelps is now all alone at the top of the career golds list, with three more chances to stretch his lead before he leaves China.
But it's no gimme going forward: Phelps must beat good friend Ryan Lochte in the 200 IM. Phelps was sixth in preliminaries, while Lochte posted the fastest time.
For Lochte, he's preparing for what could be a mission impossible. Aside from trying to beat Phelps in IM, he's working toward a rematch with defending Olympic champion Aaron Peirsol in the 200 backstroke. The two Americans qualified 1-2 for the event in which they share the world record.
Lochte ended Peirsol's seven-year winning streak in the 200 back at last year's world championships in Australia, where he also took away Peirsol's world record. The American duo resumed their rivalry resumed at the U.S. trials in July, when Peirsol avenged his loss.
Meanwhile, defending champion Amanda Beard failed to advance out of the 200 breaststroke prelims. The four-time Olympian was a sluggish 2.57 seconds off her personal best and left her 18th.
Her Olympic record was also lost, erased by teammate Rebecca Soni, who was more than a full second better than Beard's mark of 2:23.37.
Eric Shanteau's dramatic Olympic effort ended when he didn't advance in the semifinals of the 200-meter breaststroke despite swimming his personal best.
Now he will return to Atlanta for surgery on the testicular cancer he was diagnosed with last month.
'It's my best time, so I'm happy about that, but obviously it's frustrating that I'm not going to be in the final,' he said. 'I'm not going to let it weigh me down too much because I've got a much bigger battle to take care of in about two weeks.'
Alicia Sacramone made two mistakes - falling off the beam and to the mat on the floor exercise - to trigger an American collapse that handed China the gold medal.
Sacramone made her mistakes on the final two events, and Nastia Liukin and Shawn Johnson both stepped out of bounds on their ensuing floor routines. China finished with a score of 188.9 points for a blowout win over the U.S. of more than two points.
Now, Johnson and Liukin are looking ahead to Friday's all-around competition, where they're expected to battle each other for the gold to become just the third American to win the Olympic title.
Promise Isaac and Victor Obinna scored to lead Nigeria over a short-handed United States team 2-1, earning a place in the quarterfinals and eliminating the Americans. The United States played a man short from the third minute when defender Michael Orozco was ejected for swinging his elbow into Solomon Okoronkwo's chest while the players wrestled for the ball. Also advancing to the quarterfinals were the Netherlands, Cameroon, Belgium and Ivory Coast.
Zou Shiming became a national hero for winning China's first boxing medal with a bronze in Athens in 2004. The Chinese light flyweight began his effort for China's first boxing gold medal in style with an 11-2 victory over Eduard Bermudez of Venezuela.
American Deontay Wilder won his first-round match in heavyweight boxing competition with a 10-4 decision over Abdeoaziz Touiobini of Algeria. Tied after three rounds, Wilder outpointed his opponent 6-0 in the fourth and final round. He next fights Mohammed Arjaoui of Morocco. And light flyweight Luis Yanez won his opening bout with a 12-9 win over Jose Kelvin de la Nieve of Spain. His next opponent is Serdamba Purevdorj of Mongolia.
Roger Federer, who wept after losing to Thomas Berdych of the Czech Republic four years ago in Athens, avenged the loss with a 6-3, 7-6 (4) victory to reach the quarterfinals.
It was Federer's biggest victory since he lost to Rafael Nadal at Wimbledon last month, and the two could meet in the Olympics final Sunday after Nadal beat Igor Andreev of Russia, 6-4, 6-2.
Federer will next face No. 8 James Blake, who advanced by beating No. 10 Gilles Simon of France 6-4, 6-2. Blake, the lone American to survive the first round of men's singles, is 0-8 against Federer and has won only one of their 22 sets.