The men's 100 metre butterfly event, included in the swimming competition at the 2008 Summer Olympics, took place on August 14–16, at the Beijing National Aquatics Center. In this event, swimmers covered two lengths of the Olympic-sized pool employing the butterfly stroke.
American Michael Phelps won the event after coming from behind Serbia's Milorad Čavić, to beat him by one one-hundredth of a second. Australian Andrew Lauterstein won the bronze medal, finishing one one-hundredth of a second ahead of American world record holder Ian Crocker. Phelps' victory occurred after Čavić had made remarks that it would be better for the sport of swimming if Phelps was defeated. Phelps' margin of victory was so close that the Serbian team filed a protest, but, after officials reviewed the video, the International Swimming Federation (FINA) announced that Phelps did touch the wall first and his victory would be upheld.
The gold medal received by Phelps was his seventh of the Games, tying Mark Spitz's record for most gold medals won at a single Olympic Games. Other records were broken too, including the Olympic record, five continental records, and several national records.
If NOCs had no swimmers meeting the A standard, they could enter one swimmer who had beaten the B standard (54.70 seconds). If no swimmers had met the B standard, the NOCs could still enter one swimmer into the competition, provided that the swimmer had competed at the 2007 World Aquatics Championships and was approved by FINA; NOCs could use this method only if they had no male swimmers and fewer than two female swimmers in any other event.
Due to a combination of the venue, Beijing National Aquatics Center (better known as the "Water Cube"), which was claimed to be built to increase the speed of the swimmers, and the recently introduced LZR Racer swim suits, which had been proven to give the swimmer a lower time by 1.9 to 2.2%, some analysts were predicting that many fast times and world records would be set in all the swimming events.
As with almost every event that he entered in at the 2008 Summer Olympics, Michael Phelps was the favorite to win the men's 100 metre butterfly. Since winning the gold medal at the previous Games, in Athens, Phelps had demonstrated his superiority in this event, by also becoming world champion at the Melbourne 2007 World Championships, and achieving victory at the United States Olympic Trials. Therefore, the 100 metre butterfly was one of the eight Olympic events where Phelps was attempting to win a gold medal.
Going into the event, Phelps' compatriot Ian Crocker was seen as the swimmer with the best chance of beating Phelps. Crocker beat Phelps' 100 metre butterfly world record in 2003, and had since lowered it twice: once at the 2004 United States Olympic trials, and then at the 2005 World Championships in Montreal. Before the Olympics, Crocker and Phelps held the seventeen fastest times ever in the event. In 2004, Crocker was the favorite in the men's 100 metre butterfly, but lost to Phelps by four one-hundredths of a second. This victory gave Phelps the right to swim in the final of the 4 × 100 metre medley relay, however he gave up the spot to Crocker, and took his turn in the semifinals. Although holding the world record, Crocker had lost the last four times that he was up against Phelps in the 100 metre butterfly, including the 2008 United States Olympic Trials. Some thought that Crocker was not in the same shape that he was when we broke the world record, including Canadian Broadcasting Company (CBC) analyst Byron MacDonald who said that "If he's (Crocker) going to beat Phelps in Beijing, Crocker has to get close to his world record time of 50.40. He just hasn't shown it [he] can do it this year".
Another threat to Phelps' goal was Serbia's Milorad Čavić. In Athens 2004, Čavić was leading in a semifinal of the 100 metre butterfly, but right after his final turn, his suit opened at the neck and sucked in water, causing Čavić to finish last with a time of 53.12 seconds. At the 2008 European Championships, Čavić won the men's 50 metre butterfly and was the heavy favorite to win at twice that distance, but was suspended for wearing a "Kosovo is Serbia" t-shirt on the medal podium. American swimmer Gary Hall Jr. told The New York Times that although "Mike (Phelps) has been saying he’s going to win the 100 fly at the Olympics for the last year", he thought that Čavić would be the winner.
Other possible medal contenders included Andriy Serdinov of Ukraine, who had won the Olympic bronze medal in 2004, and Venezuelan Albert Subriats, a bronze medalist at the 2007 World Championships and seen as a potential spoiler, if he could match or improve on his 51.82 time, in Beijing.
The final took place on August 16, at 10:10 CST. Before the race, Milorad Čavić made headlines by saying in an interview that it would be better for swimming if he beat Phelps. Phelps' coach Bob Bowman used the quote to provide motivation to his protégé. In an interview, Phelps said that doubters like Čavić \"fires me up more than anything, I always welcome comments. It definitely motivates me even more.\" Almost immediately after the race started, Čavić took the lead with Phelps getting off to a slow start. At the turn, Čavić was first, followed by Ian Crocker, while Phelps made the split in seventh place, just 0.62 seconds behind Čavić. As the two approached the finish, Čavić tried to coast to the wall on one last stroke, while Phelps, who had misjudged the end, took an extra half-stroke, causing both competitors to touch the wall at almost exactly the same time. It turned out that Phelps had actually finished one one-hundredth of a second ahead of Čavić, with a time of 50.58 seconds. Phelps even admitted that, at first, he thought the extra stroke he took had cost him the gold medal, until he looked at the scoreboard displaying the results. Andrew Lauterstein won the bronze medal, also beating Crocker by one one-hundredth of a second.
Several records were broken at the final. For the first time at the 2008 Summer Olympics, Phelps did not break the current world record in a final, finishing eighteen one-hundredths of a second behind team-mate Crocker's 50.40-second world record from 2005; he did though set a new Olympic record. Three continental records were broken in the final, with Fujii setting a new Asian record, Čavić a new European record, and Lauterstein a new Oceanic record. Although he finished last, swimmer Ryan Pini made history as the first swimmer from Papua New Guinea to swim in an Olympic final, and even received a call from the prime minister Michael Somare congratulating him. Most notably though, Phelps won his seventh gold medal at these Games, tying Mark Spitz's record for most gold medals won at a single Olympic Games. For being able to emulate Spitz's record, Speedo, a sponsor of Michael Phelps, awarded him a US$1 million bonus, which had already been offered to him at the 2004 Summer Olympics, under the same conditions. After the final, the National Broadcasting Company (NBC) arranged a joint interview with Phelps and Spitz, where Spitz praised Phelps' effort, telling him that "what you did tonight was epic" and even though at one point, Phelps was more than half a second behind Čavić, Spitz "never thought for one moment you (Phelps) were out of that race."
The following records were established during the competition:
|August 14||Heat 7||Jason Dunford||51.14|
|August 14||Heat 9||Milorad Čavić||50.76|
|August 16||Final||Michael Phelps||50.58|