Both guys were going at it in the 4th quarter of the matchup ... and their beef even made its way to the Madison Square Garden tunnel after the game, when Melo confronted KG in a heated standoff.
Now, 8 years later, Garnett is opening up on all the drama in an interview with GQ ... and he made it clear he would never stoop that low when it comes to trash talk.
"I’ve never said anything about anyone’s family. I’ve never said anything to Melo about La La," KG said.