American Michael Phelps stayed on the gold trail as his picked up his fifth Olympic title in the men's 100m butterfly final.
The 19-year-old came from fourth place at the turn to triumph in a new Olympic record time of 51.25 seconds.
Fellow American Ian Crocker got off to a blistering start and was well ahead at the turn but he had to settle for silver as Phelps surged home.
Ukraine's Andriy Serdinov came home in third place to complete the medals.
World champion Crocker had flashed down the first 50m inside world record pace while Phelps seemed out of contention.
But the Baltimore swimmer accelerated down the return length to sneak first place and add to his individual 200m and 400m medleys and 200m butterfly crowns.
"The things I am doing right now I have dreamt about my
whole life," said Phelps.
"I am tired but I think it will be the most beautiful week of my life."
Phelps' victory saw him become the first man since the legendary American Mark Spitz to hold four individual Olympic swimming titles.
He also collected gold as part of the men's 4 x 200m freestyle team as well as bronzes in the 200m freestyle and 4 x 100 freestyle relay.
And if Phelps was a country he would be ninth in the overall medal table in Athens.