( CNN ) -- Michael Phelps repeated his record breaking feat of winning three straight Olympic gold medals in the same event with a gutsy victory in the men 's 100m butterfly Friday . It was the 17th gold medal of his remarkable career , the 21st overall , and his final swim in an individual race before retiring after the London Games . Phelps had won the 200m Individual Medley Thursday night to create Games history for a male swimmer for successive Olympic victories and was not to be denied in the sprint butterfly . The American superstar was only seventh at the turn but powered past the field to win in 51.21 seconds . South African Chad le Clos , who had pipped him to gold in the 200m butterfly , and Russian Evgeny Korotyshkin shared silver , both clocking 51.44 . `` I am just happy that the last one was a win . It 's very special , '' Phelps told BBC Sport . He will round off his efforts in the medley relay final Saturday where the U.S. are favored to win . It was to prove another superb night for Phelps ' teammates with 15-year-old Katie Ledecky upsetting home favorite and defending champion Rebecca Adlington in the 800m freestyle final . Ledecky led from the first length at the London Aquatics Centre to come within half a second of breaking Adlington 's world record set in her 2008 Beijing triumph . She touched in eight minutes 14.63 seconds ahead of Mireia Belmonte Garcia of Spain in silver with Adlington in bronze . Britain 's main hope for a swimming gold also took bronze in the 400m free . Ledecky said she received a good luck message from Phelps before the final . `` Michael is the first Olympian I ever met before I started swimming at the U.S. Nationals in 2002 or 2003 in Maryland , so to get a good luck before the race really calmed me down and I was ready to swim my race , '' she said . Adlington tried to swallow her disappointment with a defiant message . `` Everyone expected me to get a gold medal . I am so proud . I have been in four Olympic finals and got four medals , so that 's nothing to be ashamed of , but I was disappointed with the time , '' she told BBC . The third gold of the penultimate night of finals for the U.S. came from teenage sensation Missy Franklin in the women 's 200m backstroke . It was the 17-year-old 's third gold of the Games and she did it in style with a world record of two minutes 4.06 seconds to have clear water between herself and second placed Anastasia Zueva of Russia . Franklin 's teammate Elizabeth Beisel took the bronze . `` It feels absolutely amazing , I ca n't think of a better way to end my individual events , '' Franklin said . Frenchman Florent Manaudou prevented a U.S. clean sweep of gold with a shock win in the men 's 50m freestyle . Manaudou , 21 , the younger brother of former Olympic women 's 400m freestyle champion Laure , hit the took victory in 21.34 seconds . Cullen Jones of the United States took the silver with Brazilian world record holder Cesar Cielo in the bronze medal position .
Michael Phelps wins men 's 100m butterfly for 17th Olympic gold medal . Missy Franklin breaks world record to win women 's 200m backstroke . Katie Ledecky shocks home favorite Rebecca Adlington in women 's 800m . Comment: