Michael Phelps has now won a staggering 21 Olympic gold medals, following inspirational victories in the men's 200 metres butterfly and the 4x200m freestyle finals at the Rio Games.Phelps scooped the gold in the 200m butterfly final in 1 minute and 53.36 seconds, just ahead of Japan's Masato Sakai (1:53.40).
The champ had led the field through the opening three laps, however he appeared to be tiring in the final 50 metres as Sakai looked to pounce.
They effectively went stroke for stroke as they approached the wall, with Phelps finding enough in the tank to out-touch the Japanese. Hungarian Tamas Kenderesi took the bronze in 1:53.62.
It is Phelps' third Olympic 200m butterfly gold, following victories in 2004 and 2008.
The 200m butterfly is particularly close Phelps' heart — he finished fifth in the event at the 2000 Sydney Olympics as a 15-year-old and was awarded silver four years ago following his wins in Athens and Beijing.
The 31-year-old had tears in his eyes as he stood on the medal podium as the United States national anthem played out in front of a captive audience at the Olympic Aquatics Centre.
Family man Phelps shares special moment with young sonPhelps and his fellow medallists later made their way around the pool deck. Phelps stopped to kiss and his mother Debbie, fiancee Nicole and young son Boomer, a moment that captured how much the victory meant to the Phelps family following his turbulent return to competitive swimming in 2014.
Phelps highlighted how special it was to share the win after the medal ceremony with his son, who was born in May.
"I wanted to hold him longer," he said.
"But I have FaceTime with them every night. It was good to see he was awake, he usually just sleeps all the time so it is good to see he was awake."
He had retired after the 2012 London Olympics, but reversed his decision two years later, before his comeback was almost derailed after a stint in rehab that followed a drink-driving arrest in the US.
The largely Brazilian crowd appreciated his performance in the pool on Tuesday night, chanting "Phelps, Phelps, Phelps" and "USA, USA, USA" after he secured what was then his 20th gold medal.
Phelps later anchored the US to victory in the 4x200m freestyle final, the Americans winning in 7:00.66, ahead of Great Britain (7:03.13) and Japan (7:03.50). Australia was fourth in a time of 7:04.18.
Phelps, a five-time Olympian, now has 25 Olympic medals in his keeping, and the 4x200m freestyle win was his ninth in the relay events.
"I was talking about it the other night and I guess one of the things that is really kind of sticking in my head more is that is a lot of medals, we've got a lot of medals," Phelps said.
"It's just insane. It's mind blowing almost to me. To think about when this all started ... it's just special.