The former NBA star, 41, took on the 33-year-old singer at the Showboat Casino in Atlantic City and was victorious within two rounds of the three-round competition.
While both stars came out swinging, onlookers insisted that Lamar - who is 10 inches taller than Aaron - was clearly in control from the beginning.
Aaron went down halfway through the second round, TMZ reports, but there were no hard feelings as the pair shared a hug at the end.
Lamar had previously predicted that he would knock Aaron out in the first round.
"It's not gon' be a fight. It ain't gon' be a fight," he had said.
When asked if he could knock Carter out in the first round, Lamar said, "Yeah. Probably, I would say the first minute."
Meanwhile, celebrity boxing honcho Damon Feldman previously revealed that both stars were training hard for the event and were taking the fight "very seriously."
"It's gonna be a war, man. It's gonna be a knockout, no doubt," he added.
Meanwhile, roughly a week ago in Florida, retired boxing champion Floyd Mayweather, Jr. returned to the ring to face off [c=Logan Paul in an exhibition match at Hard Rock Stadium in Miami Gardens.
Since it's an exhibition fight, no winner was announced and the judges didn't keep score. The fighters landed just 73 punches combined, with Floyd landing the majority of them and Logan struggling to find his target. The fight was deemed underwhelming by boxing fans.