It was his first victory in the three-day Arena Pro Swim Series that serves as the start of the gear-up for the 2016 Rio Olympics. That he was nowhere near satisfied with his performance might show he is rediscovering the competitive fire that made him the winningest athlete in Olympic history.
The Baltimorean led from start to finish in 1 minute, 59.30 seconds at the University of Minnesota. He finished more than 1 second ahead of fellow Olympian Conor Dwyer (2:00.73), but was left lamenting all the mistakes he made.
"I'm happy that I was about where I was at the end of last season before nationals," Phelps said. "And it was still with a terrible last 50 and a bad finish."
The event was the kickoff to a seven-city tour that is part of the buildup to the Summer Games.
On the final night of swimming at the series, Simone Manuel bested a star-studded field in the women's 100 freestyle with a time of 54.19 seconds. Manuel used a strong final 50 meters to beat Abbey Weitzeil and Allison Schmitt of North Baltimore Aquatic Club in a field that also included Olympic champions Katie Ledecky of Bethesda and Missy Franklin.
"I get nervous for most all my races," Manuel said. "But I think it's pretty cool to be up there with such amazing athletes and to be able to race against them. Just being able to race against a good field is always fun and exciting.
Ledecky won the 800 free to go along with victories in the 200 and 400 freestyles earlier this week, and Franklin's victory in the 200 backstroke was her second in as many nights at the Jean K. Freeman Aquatic Center.
"I am beyond ecstatic about that," Franklin said of her time of 2 minutes, 7.24 seconds. "I am so, so happy. Definitely learned so much, too, which is the point of these meets."
Phelps finished second in the 200 butterfly and third in the 100 fly earlier this week as he continues to work his way back from a brief retirement that came after the 2012 London Games. The 18-time gold medalist was barred from the world championships in Russia after his second drunken driving arrest, but has since recommitted himself to the sport he dominated for so long.
He was overpowering at the national championships in August and left Minneapolis saying he would "continue to take baby steps" as he ramps up to compete as a 30-year-old in Rio.
"I think coming off of this it's really just working on all the small things," Phelps said. "We've gotten to the point where we're really in shape again. Now it's just paying attention to hitting the walls right and the finishes."
Ledecky held off Becca Mann of NBAC in the 800 free with a pool record time of 8 minutes, 19.16 seconds.
"I'm happy with how I swam here," Ledecky said. "I think my shorter events were a little better than my longer events, but I think that's just from being in some pretty tough training. It felt good to get back into racing."
In other events, Nathan Adrian won the 100 free (48.49 seconds), Caitlin Leverenz won the 200 IM (2:11.24), Michael McBroom won the 1500 free (15:14.82) and Arkady Vyatchanin finished first in the men's 200 backstroke (1:57.30).
The circuit this season features $350,000 in prize money, with $1,000 for first place, $600 for second place and $200 for third place in each event. The overall winner for each gender for the entire seven-event series will get $10,000.
"I'm just kind of having fun and really just enjoying it," Phelps said. "But it does feel good to be picking up where we left off at the beginning of last year."