'Mind-blowing' - Emotional Michael Phelps on bringing his Olympic gold medal tally to 21
An emotional Michael Phelps reflected on a "mind-blowing" career after taking his Olympic gold medal-winning tally to 21 with two wins on the fourth night of finals at the Rio Games.
Phelps won a 20th Olympic gold - and 12th individual title - with a dominant victory in his signature event, the 200 metres butterfly, before anchoring the United States to gold in the 4x200m freestyle relay.
A disbelieving Phelps was still absorbing his achievement as the most decorated Olympian in history, with 25 medals in all, when he targeted further success in his fifth and final Games.
"That's a lot of medals," he said. "It's just insane. It's mind-blowing.
"I wanted that one back. I came into the pool tonight with a mission and the mission was accomplished.
"Looking forward to the rest of the week and I'm not even halfway done yet."
He has three more opportunities and a possible seven races in Rio, his final Olympics, in the 100m butterfly, 4x100m medley relay and 200m individual medley, which begins on Wednesday.
The "mission" was a cathartic victory in the event in which he made his name, finishing fifth in the Sydney Olympics 16 years ago, aged 15.
South African Chad le Clos had shocked Phelps, the 2004 and 2008 Olympic champion, by winning gold ahead of his idol at the London 2012 Games.
Phelps retired after those Games, as planned, but he returned 18 months later with unfinished business.
"I told Bob (Bowman, his coach) when I came back how bad I wanted that 200m fly," added Phelps, who puffed his cheeks out on the podium, trying to contain his emotions.
"That being my very first Olympic event, to be able to win it in my fifth Olympics is pretty special.
"It was really just going through the last 16 years. That event was my bread and butter. That was the last time I'll ever swim it.
"Having that come to an end is weird, it's crazy to think about.
"What happened four years ago is still with me. It was a frustrating race for me.
"There wasn't a shot in hell I was losing that tonight. And, if I did, every ounce that I had was left in the pool.
"Just being able to see the number one next to my name again, one more time in the 200 fly, couldn't have scripted it any better."
The journey from London to Rio was not a straightforward one, featuring an arrest for drink driving and a subsequent suspension which saw him miss last year's World Championships in Kazan, Russia.
He had a face of thunder, shaded under a hood, as Le Clos was seen shadow boxing in the call room before Monday's semi-final.
With the medals on the line, the prizefighters were ready for round two in Tuesday night's final.
Both Le Clos' parents - mum Geraldine and father Bert, whose exuberant celebrations captured the public's imagination four years ago - have cancer. But there was no emotional victory this time round.
Le Clos had done plenty of talking in the lead up; he was so devastated to finish fourth he did not speak afterwards.
Phelps reclaimed the title with a block to wall victory in one minute 53.36 seconds, reigning supreme before celebrating with his mum Debbie, fiance Nicole and infant son Boomer.
"It was good to see he was awake. I wanted to hold him longer," Phelps said of his baby boy.
He did not realise the small margin of victory - just 0.04secs from Japan's Masato Sakai.
"The last 10m, oh my gosh I thought I was standing still," Phelps added.
"When I took a half-stroke I thought the same thing as '08 (in the 100m butterfly in Beijing). I thought that cost me the race, but that won me the race."
In the relay, Phelps' team-mates gave him a comfortable lead ahead of the final leg.
Conor Dwyer even gave Phelps his hat after Phelps' split.
Dwyer said: "I finished my leg and he tapped me on the shoulder when I was cheering Townley on and I heard him say 'Didi, look at my cap, I don't have a cap'.
"We have different sponsors. He had to wear an all-black cap, so we reversed it, put it on.
"And we've seen that guy go through a lot of adversity, like winning gold medals without goggles on.
"A different cap won't stop that guy from having a good split."
Once the relay was won, Phelps took a moment to himself and sat on the block at the end of the lane.
"Doing a double like that is a lot harder now than it once was," he said.