American swimmer Phelps doing it his way on Road to Rio

OMAHA, NEBRASKA: Determined to exit swimming on his own terms, Michael Phelps cleared a major hurdle on the road to Rio on Wednesday, qualifying for a fifth Olympics with a victory that has paved the way to more Games glory.

Inspired, motivated and sober, Phelps heads to Rio thanks to his 200 metres butterfly win at the U.S. Olympic trials with the goal of adding to his staggering record total of 22 medals, including 18 gold, and pen a happy ending to a brilliant career that he feels he denied himself at the 2012 London Olympics.

"Coming back and being able to have the opportunity to finish how I want," said Phelps, of his motivation. "I'm doing this because I wanted to.

"Thinking about the ups and downs we've gone through in and out of the pool to get to this point and not feeling an absolute 100 percent but still being able to get the job done.

"I think things are probably going to hit me a lot more emotionally now than what they would have in the past, because I'm enjoying the moment and I'm embracing the moment."

For Phelps, this Olympic journey is more important than the destination, a trip into retirement that he is determined to share with his fiancee Nicole and infant son Boomer, who were among the sellout crowd of 14,000 at the CenturyLink Centre.

At London, which he had declared to be his last Games, Phelps won four gold and overall six medals but walked away with the regret that he simply went through the motions.

He subsequently talked of a golf career but eventually found himself testing the waters of a swimming comeback which was interrupted by a second drunk driving arrest in 2014 and a stint in rehab that laid the foundation for Phelps' transformation from a party boy to a family man.

After accepting his medal for his 200 fly win, Phelps searched the darkened arena for his partner and child, joining them poolside where he hugged Nicole and planted a kiss on his son's forehead.

"I wanted to go over, and I've always given my family my flowers and stuffed animal, I guess that's his (Boomer's) first stuffed animal from a race," said Phelps, who will have Nicole and Boomer join him in Rio despite the Zika threat. "I just wanted to share that with them.

"I don't see him every day. I try to, but if I do it's for a very short moment, so any time I have with him is always very special."

While Phelps, who will celebrate his 31st birthday on Thursday, has turned his life around away from the pool, in the water he remains as demanding and critical as ever.

Aside from the result, very little in his 200m swim on Wednesday evening pleased Phelps, the winning time of 1:54.84 well off his world record mark of 1:51.51.

"Awful," declared Phelps when asked to assess the last part of his swim. "The piano felt pretty hard.

"I think with everything that has happened and being able to come back that was probably harder than any swim I have had in my life.

"I haven't felt great in the water but like I said, I'm checking a box off, being able to get on the team.

"Getting on the team was the most important thing and that was the only thing I had to do tonight."