Michael Phelps added yet another Olympic medal to his record total, winning a gold medal in the 200-meter butterfly Tuesday night to give him a total of 24 medals.
Masato Sakai of Japan took the silver medal while Tamás Kenderesi of Hungary won bronze.
After advancing from the prelims on Monday, Phelps posted the second-fastest time in the semifinals later that night, trailing only Hungary's Kenderesi.
The 19-time Olympic gold medal winner posted the third-fastest time in his preliminary heat on Monday, good enough for fifth fastest overall and a spot in the semis.
His American teammate, Thomas Shields, wasn't as lucky, finishing sixth in his prelim heat and 20th overall on Monday to miss advancing.
Phelps was swimming in his fifth 200m butterfly Olympic final, having won silver in 2012 to go along with the golds he won in 2008 and 2004.
Phelps opened his fifth Olympics on Sunday night by helping the U.S. to gold in the 4x100-meter freestyle relay.
He is also scheduled to swim in the 100m butterfly and the 200m individual medley and will be part of the U.S. team defending the 4x100-meter medley relay gold he helped win in London four years ago.