Inge de Bruijn, who had lost two of the three Olympic titles she won in 2000, saved her best for last to retain the 50 metres freestyle crown in the concluding swimming session of the Athens Games on Saturday.
De Bruijn, 31 next Tuesday, had asserted her domination in both heats and semi-finals on Friday, finishing the best part of half a second faster than anyone else.
The final was tighter but she had established a lead in the one-length dash midway through the race and held on to win in 24.58 seconds.
She is the first woman to retain the Olympic 50 freestyle title, which was introduced in 1988.
Malia Metella of France, fourth in the 100 freestyle on Thursday, snatched the silver in 24.89 while Libby Lenton, who lost her 100 freestyle world record to fellow Australian Jodie Henry and failed to make that final, gained compensation with the bronze in 24.91.
Sweden's Therese Alshammar, double Olympic freestyle silver medallist behind De Bruijn in 2000, finished just out of the medals, a tantalising 0.02 seconds behind Lenton in fourth place.
American Jenny Thompson, who has competed in five Games and matched Mark Spitz with an aggregate 11 career Olympic medals when she picked up a relay silver on the opening day of competition, finished back in seventh place in 25.11
De Bruijn had to settle for bronze in Sunday's 100 metres butterfly and silver in Thursday's 100 freestyle but nobody in the 50 freestyle, the shortest Olympic race, ever looked capable of dethroning the Dutch sprinter.
De Bruijn was world champion in the event in 2001 and 2003 and the world record of 24.13 set at the 2000 Sydney Olympics still stands.
