The Grizzlies superstar had been barred from the court to start this season while serving a 25-game suspension for a string of incidents involving gun-related social media videos ... but in his return against the Pelicans on Tuesday night, his presence was felt right away.

He logged 34 points and 8 assists on the road game in New Orleans -- but, most importantly, he nailed a floater in the lane with no time left in regulation to win the game for Memphis, 115-113.

And, afterward, he had a big-time message for his haters ... saying simply as he ran into the locker room, "I kept receipts!"

Morant, of course, had developed a bevy of critics after he was seen on social media waving around a gun not once, but twice. He had also been accused last year of attacking a teenager during a pickup game at his home. It all eventually led to NBA commish Adam Silver sidelining him.

But, Morant took all the steps the NBA and the Grizzlies required for him to rejoin the team ... and after his big night against the Pels, he said there were certainly some low points while he was away from his teammates.

"I haven't played a game in eight months," he said. "I had a lot of time to learn myself, a lot of hard days where I went through it. But, you know, basketball is my life, what I love. It’s therapeutic for me and I'm just excited to be back."