Shanghai - American great Michael Phelps won the 100m butterfly in convincing fashion on Saturday to prove he is far from a spent force in swimming despite a disappointing world championships.
The defending champion, world record-holder and Olympic gold medallist was third at the turn but he swept through the field over the final 50 metres to win in 50.71sec, ahead of Poland's Konrad Czerniak and America's Tyler McGill.
With nemesis Ryan Lochte watching from the stands, Phelps extended his record number of world titles to 25, including three in Shanghai, alongside two silver medals and one bronze.
Phelps returned to China looking for a possible seven golds, to follow his eight from the 2008 Olympics, but he was beaten by Lochte in the 200m freestyle and again in 200m individual medley, where his team-mate set a world record.
The United States also enjoyed success through 16-year-old Missy Franklin, who claimed her second title -- and fourth medal overall -- with a dominant victory in the women's 200m backstroke.
Franklin was never behind in the race and she won it convincingly in 2min 5.10sec ahead of Australia's Belinda Hocking and Sharon van Rouwendaal of the Netherlands.