EAST LANSING, Mich. (AP) Tom Izzo figures this game was payback for some of the tough losses his Michigan State team endured earlier in the season.
''Today's one we should have lost that we won - but I can tell you three we should have won that we lost,'' Izzo said Sunday.
Travis Trice had 18 points and 10 assists, and Michigan State outlasted Northwestern 84-77 in overtime. The Spartans held the Wildcats without a point in the extra session until the final minute.
Denzel Valentine scored 17 points for Michigan State, and Branden Dawson and Gavin Schilling added 13 each, but Izzo wasn't all that happy with his team's third straight win.
''Every time I think we're taking a step forward, to me, we take a step back, and the performance today was not one that I'm very proud of,'' he said.
The extra session was finally kind to the Spartans, who had lost their first three overtime games this season, including a double-OT defeat against Maryland late last month. Michigan State (12-5, 3-1 Big Ten) had a 14-point lead in the first half, but that was gone by halftime, and Northwestern (10-6, 1-2) also rallied from an 11-point deficit in the second.
Bryant McIntosh led Northwestern with 18 points. Tre Demps added 17 and JerShon Cobb had 12.
''I'm heartbroken for my team because I felt we deserved to win the game,'' Wildcats coach Chris Collins said. ''I just thought our guys were really good today. I thought we made a lot of plays down the stretch.''
Northwestern shot 12 of 25 from 3-point range.
''It feels good to finally win a close game, but we shouldn't have let it get that close,'' Valentine said. ''We can't stop playing, and that starts on defense. We can't win many Big Ten games when teams shoot like that.''
Michigan State went on a 17-2 run in the second half to take a 66-55 lead, but Northwestern shot its way back into the game. Back-to-back 3-pointers by Vic Law and Demps tied it at 68, and when Demps made two free throws with 28 seconds left, the Wildcats led 72-70.
Valentine drew a foul at the other end and made both his free throws, and Demps missed from the perimeter in the final seconds of regulation.
Michigan State scored the first eight points of overtime.
The Spartans scored the game's first nine points and led 23-9 after a four-point play by Bryn Forbes. Collins was called for a technical foul for arguing with 9:42 left in the half, but the Wildcats eventually found their touch from the outside. They shot 7 of 12 from beyond the arc in the half, and it was tied at 40 at halftime.
A 3-pointer by Nathan Taphorn gave the Wildcats a 53-49 lead, but Dawson and Valentine helped Michigan State build another double-digit lead.
Northwestern: The Wildcats haven't won at Michigan State since 2009.
Michigan State: The Spartans were playing their third game in seven days, while Northwestern was playing its first in that span. ... Izzo improved to 31-4 against Northwestern.
Cobb made all five of his field goal attempts in the first half, but he played only eight minutes the rest of the way.
''Someone landed on his foot so he couldn't play. He had to come out of the game,'' Collins said. ''That really hurt us, because he was playing really well.''
Valentine played 34 minutes, although Izzo said he's ailing and Matt Costello hasn't looked right either.
''Denzel looks out of it, Costello looks out of it,'' the Michigan State coach said. ''It's not their attitude or anything. It's just, they can't get their first wind, much less their second wind, and I don't know why. We're going to get them tested to see if there's something really wrong with them.''
Five Michigan State players scored in double figures. The Spartans are 8-0 when at least four players score at least 10 points.
Northwestern: Hosts Illinois on Wednesday night.
Michigan State: Plays at No. 11 Maryland on Saturday.