Michigan State had a 63-50 lead at Northwestern with just over three minutes remaining in Monday's game before the Wildcats scored 12 unanswered points to make it a 63-62 game with 28 seconds remaining.
Draymond Green's rebound and put-back on a Kalin Lucas missed field goal allowed the Spartans to close out a 65-62 win.
"It's going to be one of those years for us," Michigan State coach Tom Izzo said. "Nothing is going to be easy.
"You expect your best players to make big plays. I'm happy for him (Green). He started out like it would be a monster night for him. I guess it was. He had a double-double."