PHOENIX – Michael Phelps suffered a narrow loss to old rival Ryan Lochte in his comeback to competitive swimming on Thursday, but still showed enough to suggest he will be a force to be reckoned with.

Racing for the first time since he retired in a blaze of glory after the 2012 London Olympics with a staggering career total of 18 gold medals, Phelps won his morning heat in the 100-meter butterfly then finished runnerup to Lochte in a close final.

Lochte, a five-time Olympic gold medalist who beat Phelps to win the 400 individual medley at London, touched the wall first in 51.93 seconds with Phelps just behind in 52.13.

Phelps’ time was well outside the world record of 49.82 he set at the 2009 world championships but still safely under the qualifying standard for the U.S. national championships in August, which double as the selection event for next year’s world championships in Russia.

Although the 28-year-old still holds the world record in three individual events, none of his past times count for future competitions because they were recorded before the qualifying period began in June 2013.

The last time Phelps needed to post a time to qualify for the national was when he was 13.

Phelps and his coach Bob Bowman were both reluctant to talk about their long-term goals but neither has ruled out the possibility of competing at the 2016 Rio Olympics.

“I could tell when he came in and I first saw him warm up that it was going to be good, that he was feeling good and he was into it,” Bowman said after the heats.

“I’m just glad he came out of the race and he’s got one under his belt.

“He’s qualified for nationals so let’s see what’s down the road. He has an opportunity if he wants to take advantage of it.”

Unshaven and still 3 kg over his ideal racing weight, Phelps was a model of composure in the morning heats, chatting and joking with his competitors and uncharacteristically smiling to the crowds, which included his mother.

But he looked more like his previous incarnation when he arrived for the evening final, climbing the starting blocks with the glazed look of a prize fighter determined to win.

“I’m more relaxed now that I ever was,” Phelps said.

“I felt like a summer league swimmer today. I was just so excited. I felt like I should have my lane and heat written on my hand in case I forget it.

“I didn’t want to wait any more. I didn’t want to sit on the massage table any more. I wanted to get this first race done.”

Tickets for the event sold out within hours after Phelps confirmed he was making his comeback and were selling for more than six times their face value on the secondary market.

More than 100 media — a 500 percent increase on last year’s meet — descended on the Skyline Aquatic Center to see him take his first plunge back into the water.

Even before his race, the crowd lining the warmup pool was five deep with people trying to snap a picture of him practicing with his kick-board while a television helicopter buzzed above the pool.

Gregg Troy, who was previously the personal coach of Lochte and the head coach of the U.S. men’s team at the London Olympics, said it was great for the sport to see Phelps back.