Competing for just the second time since retiring after the 2012 London Olympics, Phelps ticked off all the important boxes he needed to.
In the morning heats, he tested his stamina by entering two lung-sapping events — the 200-meter freestyle and 100 butterfly — then he tested his speed by winning the 100 butterfly final in the evening.
He also qualified for the 200 freestyle final but pulled out of the race after achieving his goal in the heats: qualifying for this year's U.S. national championships, which double as the selection event for next year's world titles in Russia.
His time in the 200 free was 1 minute, 51.69 seconds, way below his best, but 0.2 of a second inside the U.S. qualifying time.
His best times from previous years don't count for future meetings because they happened outside the qualifying window, but Phelps now has qualified for the nationals in the 100 butterfly and 200 freestyle.
Phelps and longtime coach Bob Bowman have been coy about their future plans, but Bowman was pleased by what he saw Friday.
"I thought Michael's 200 free was actually pretty good for the first one in a couple of years," Bowman told reporters.
"Now we have a real picture of where he is at. I think he could definitely do better."
Phelps is unlikely to swim the more grueling 200 freestyle in individual events, but he needs to enter it at the national titles if he wants a place on the 4x200 relay team.
"I thought technically he was pretty good," Bowman said. "He was much better than he's been in training so far, so he's definitely improving in that stroke, and I think as he goes along, that will get a lot better."
The 100 butterfly is one of two individual events Phelps won at three straight Olympics. And if he qualifies for the event at the 2016 Rio Olympics, he will automatically make the U.S. men's medley relay, which has never been beaten at the Olympics.
Lochte was not in the race, watching from the stands as he recovers from a knee injury, allowing Phelps to coast to victory.
His time of 52.13 seconds was slightly below his best time in Phoenix but enough to register his first win since he retired and send an ominous warning to his rivals that he is back.