Golovkin had his opponent wobbling in the opening round with a right-hand knockdown but had to wait for his 29th career victory, eventually ending the contest with a clever jab which sent Adama sprawling to the canvas.
The Kazakhstan heavy-hitter, who has been linked with a possible 2014 battle with Britain's Carl Froch, also put Adama down in the sixth and seventh before a left hook straight after the final count prompted the referee to step in.
It was GGG's 16th consecutive knockout win, and he is fast running out of credible opponents with few boxers willing to take him on.
"I feel terrific, I'm very happy with my performance," Golovkin said.
"From the opening round I was comfortable with the fight and felt good about my power and the pace of the fight. He was a tough opponent but I was never hurt."