The Timberwolves will face the Golden State Warriors or the Houston Rockets in the Western Conference semi-finals.
The Rockets kept their play-off hopes alive with a 131-116 win against the Warriors in game five, cutting their series deficit to 3-2.
Fred VanVleet scored 26 points for the Rockets, while Amen Thompson added 25 and Dillon Brooks 24 at Toyota Center.
The Rockets led by 31 points at one stage, and Warriors coach Steve Kerr substituted many of his starters in the third quarter in order to keep them fresh for game six.
“We can’t come out with that lack of defensive focus and energy and expect to beat a great team on their home floor,” said Kerr.
“They took it to us – they were awesome tonight.”
Game six takes place at 02:00 BST on Saturday at Chase Center in San Francisco.
