Sinner extended his current winning streak to 30 matches when he lit up Court Philippe-Chatrier with another polished display to ease past wild card Clement Tabur 6-1, 6-3, 6-4.
"I'm very happy to be back here," Sinner said in his on-court interview. "It's a very special place and I have great memories overall. First-round matches are never easy, but it's even more special to start the tournament during a night session, so thank you all for staying out."
The four-time major champion will next meet Juan Manuel Cerundolo in the second round in Paris.
Elsewhere, fourth seed Auger-Aliassime came back from the brink of defeat in his opening match against Daniel Altmaier, as he found a way to win 4-6, 6-4, 4-6, 6-1, 7-6(7) in an epic first-round clash.
Auger-Aliassime has jumped up to a career high No 4 in the ATP Live rankings, but his hopes of remaining in that position rest on how well he performs at this second Grand Slam of the tennis year.
If the Canadian had crashed out in the first round, there is every chance he would have slipped down the rankings when they are updated at the end of the French Open.
Now he lives to fight another day, even though he admitted he was pushed to the brink by an opponent who has a history of upsetting top 10 players in big tournaments.
"There are ups and downs during the match, but in the end, winning matches like that is what made me dream when I was little, to experience emotions like that in front of a packed crowd on a prestigious court like Suzanne-Lenglen," Auger-Aliassime said.
"So I really enjoyed myself. It wasn't easy every time, but in the end, winning is pure joy. Honestly, there are no tactics left at the end. It's every single ball, every single ball, you give it your all on every single ball and you try to do your best.
"You try to take your time, to breathe properly between points, but in the end, once the point starts, you play with your heart, with your gut.
"Of course, there can only be one winner and obviously I'm very happy that it's me today. I also have to give credit to Daniel, who played a great match today. We've always had some good battles, he and I.
"I think I was a different player after the third set. I took a little break in the locker room and I think I cleared my head and I think I came out with renewed energy."
World No. 68 and clay court specialist Roman Andres Burruchaga lies in wait for Auger-Aliassime.