Peaty's victory in Japan, which followed his 2016 triumph in Rio, leaves him with the chance of equalling American great Michael Phelps as the only male swimmers to have won the same event at three successive Olympics.
That achievement would be all the more impressive given the mental health issues the 29-year-old has battled.
Speaking to reporters after his heat, Peaty struck a relaxed and content tone as he looked ahead to his semi-final later on Saturday and then Sunday's final.
"I saw the scores come in, I was like I don't really have to push anything too far, I don't have to prove anything, but we'll see what we get tonight. We can't win the battle now, we have to win it tomorrow," he said.
Peaty, who has struggled with depression, among other issues, said he was feeling calm.
"Yeah very good. If anything too relaxed in the sense of, it doesn't feel like we're here at the moment but getting that swim done starts to wake up the mind and I think that's just experience where I know I don't have to spend the energy here," he said.
The full and loud crowd at the La Defense Arena was in marked contrast to the mostly empty seats at the COVID-impacted Tokyo Games but Peaty said the atmosphere wasn't the only difference.
"Very, very different, very different but I was a younger man, a little bit more to prove and a little bit more angry back then so obviously tonight we've got a nice job to do and our field is a little bit closer so we're going to have to go an A game just to make sure that we get through to that final in a good lane," he said.
Peaty has been outspoken in his concerns over doping in the sport, wading into the rows around the handling of the 23 positive test results for Chinese swimmers who were cleared to swim before Tokyo, but he said he was trying to focus now on the task in hand.
"I mean it's always in the back of your mind as an athlete, you know, you definitely want a fair game, you want to win fair and be around people who do that same and live by the same values and that's all I'll say on that," he said.
"I think we all know what we're talking about but at the same time we've got a job to do so we can't let that be a cloud in front of the road."
