Garnett was playing in his second home game since being reacquired by the Timberwolves, and he picked up a technical in the second quarter from referee Eric Lewis for arguing a foul call.
Then in the third quarter, Garnett slammed the ball down in frustration after a foul on Jeff Green. Referee Bennett Salvatore quickly issued a technical foul, prompting Garnett's ejection.
It was a disappointing outcome for more than 19,000 fans who came to the game to cheer Garnett, the biggest star in franchise history.
Garnett had six points, three rebounds and three steals in 15 minutes.