The move, with just over four minutes left in the third quarter at Gainbridge Fieldhouse, saw Morant cut in from the right before leaping over Jalen Smith and slamming in a spectacular dunk that had his team-mates and even opposition fans left in visible awe.
The Grizzlies went on to win 130-112 to make it nine victories in a row, and Morant – who ended with 23 points, 10 assists and three rebounds – agreed the dunk was the best of his career so far.
"Yeah, easy," he said. "It's what everybody has been waiting for. I finally made it."
Kevin Durant and Kevin Garnett were among those to react on Twitter to Morant's effort, with the latter exclaiming: "When we look back on Ja's in game dunk highlights when it's all said and done it's gonna be up there with some of the greatest ever."
Desmond Bane, who top-scored for the visitors with 25 points, also acknowledged the effort of his team-mate, saying: "I ain't seen nothing like that one. That's probably going to go down as dunk of the year."
Memphis' win streak has taken them to 29-13 as they fight with the Denver Nuggets for superiority in the Western Conference, though coach Taylor Jenkins acknowledged his team is "not playing perfect basketball."
He was, though, happy to see the Grizzlies "finding different ways to win," adding: "Whether we're playing with a lead or playing from behind. Each game has presented a different challenge for us and our guys have stayed the course.''
Pacers coach Rick Carlisle was clearly impressed by their performance, saying: "[The Grizzlies may] very well may be the best team on the planet right now.''