Michael Phelps closed out his Olympic campaign the only way imaginable, with a gold medal.
Phelps took part in the 4x100 metre relay along with Nathan Adrian, Ryan Murphy and Cody Miller.
The United States were in second when Phelps entered the water.
Phelps did the butterfly leg of the race.
The 31-year old announced yesterday that he was "ready to retire."
Phelps ends his career with 23 gold medals in 30 Olympic races.
Newshub.