Michael Phelps won the 19th gold medal of his Olympic swimming career on Sunday after helping the U.S. men's team to victory in the 4x100m freestyle relay.
The 31-year-old, making his first competitive appearance in the pool at his fifth Games after sitting out the heats, now has an unprecedented 23 medals with two silvers and two bronzes filling out his tally.
London 2012 champions France took the silver medal and Australia the bronze.
Swimming second in the relay, Phelps took over from Caeleb Dressel, just 0.02 seconds behind France and in a few powerful strokes the 31-year-old gave his team the lead.
"Caeleb wanted to get out in open water, lead us off and the only thing I said to them 'I'm going to try and get you guys as much open water as I can'," said Phelps.
"I know how hard it is to swim in the wake in that race and I was going to do whatever I could to get them out front."
Ryan Held increased the lead and London individual 100 freestyle champion Nathan Adrian brought them home as the chants of "USA! USA!" rose to a crescendo.
"It was crazy, I was standing on the block while Caeleb (Dressel) was coming in and I actually thought my heart was going to explode out of my chest," said Phelps.
"Having the amount of excitement cheering in the stands during that race I don't know if I have heard anything like it."
