RIO DE JANEIRO (AP) When Michael Phelps arrived in Rio as a 31-year-old swimmer who retired once and endured plenty of turmoil away from the pool, everyone wondered just how many gold medals was a realistic goal.
How does six sound?
In his first appearance of these Summer Games, Phelps showed he is still capable of the kind of jaw-dropping, did-he-really-just-do-that? performances that already made him the most decorated Olympic athlete of them all.
Going second in the 4x100-meter freestyle relay, Phelps produced the fastest split of his career and put the Americans out front for good against a powerhouse field that included defending champion France, Australia and Russia.
It was a down-and-back swim that showed Phelps, as usual, is in peak form on the biggest stage and perfectly capable of winning every race he enters at his fifth Olympics.
''Michael usually works this way: When one thing is good, everything is pretty good,'' said his longtime coach, Bob Bowman. ''It doesn't usually work in parts. So I feel pretty good now.''
He has every reason.
Phelps will be back at the pool Monday for the preliminaries of the 200-meter butterfly, a title he is especially eager to reclaim after an ill-timed finish let South Africa's Chad le Clos snatch away the gold at the 2012 London Games.
Phelps will also compete in the 100 fly and 200 individual medley, as well as two more relays.
His confidence is soaring after he turned in a time of 47.12 seconds in the relay, which was faster than all but three other swimmers in the field - all of them anchors on the medal-winning teams and specialists in the 100 free.
In fact, it was faster than any of his relay splits at the last three Olympics. Yep, even faster than the one he produced at the height of his career in 2008, when he broke Mark Spitz's longstanding record with eight gold medals in the Great Haul of China.
''I hope that's a good sign,'' Phelps said. ''I guess we'll see over the next couple of days. But I'm very pleased with the start.''
France had high hopes for defending the title it won four years ago in London, only to be doomed by another Phelps masterpiece.
''As fast as my teammates were, the extraterrestrial that is Phelps was faster,'' said Fabien Gilot, who had the unfortunate task of swimming the second leg for the now-silver medalists.
Gilot's time was more than a second slower than Phelps, which was essentially the deciding factor in the race. The French were faster on the first and third legs, and anchor Jeremy Stravius was only 0.14 slower than the last American swimmer, Nathan Adrian.
The Australians, with plenty of big names of their own, settled for the bronze. They didn't mind being on a lower rung of the podium, considering who was on top.
''It's always great to see a fairytale like that unfold in a race you're a part of,'' James Magnussen said.
Phelps' showing was reminiscent of the dominance he showed last summer in San Antonio, where he competed in a low-level meet because he was banned from the world championships as part of his punishment for a second drunken-driving arrest. Thoroughly motivated, Phelps put up times that were faster than the ones winning at worlds.
The DUI proved to be a turning point in Phelps' life, prompting him to under six weeks of inpatient therapy, give up drinking, reconnect with his estranged father, and find a new purpose in his life away from the pool.
He wound up getting engaged and becoming a father for the first time. His infant son, Boomer, was in the stands Sunday night, nuzzled in the arms of mother Nicole Johnson, the roaring crowd kept at bay by noise-canceling headphones.
Still, this was all a bit of a surprise after Phelps turned in some rather lackluster times at the U.S. Olympic trials just a month before the Rio Games.
About a week ago, during a final training camp in Atlanta, Phelps did a 100 free time trial. At that point, according to Bowman, his spot on the 4x100 free relay was very much in doubt.
''He was very much into it,'' Bowman said. ''He wanted to do it. I felt like we had to give him that chance. He hadn't really done a good 100 free in the season. I felt like after we got out of San Antonio, I knew he was so much better. So he needed to do that.''
As usual, Phelps came through.
''It was the fourth-fastest flat-start time of the year,'' Bowman said. ''That kind of automatically put him in the game.''
Now, it's clear that Phelps has peaked at just the right time, eager to close his career on top after initially retiring four years ago coming off the London Olympics.
''He's in a good place now,'' Bowman said. ''Everything I've asked him to do, he's been really good at, way better than before trials.''
Suddenly, six gold medals seem very much in reach.
Follow Paul Newberry on Twitter at www.twitter.com/pnewberry1963 . His work can be found at http://bigstory.ap.org/content/paul-newberry .