Northwestern lives by the three-pointer. Wednesday night against Michigan State, the Wildcats died by it.

Just a week ago, the Cats held Illinois to 26 percent from beyond the arc and garnered 24 points off threes of their own. But NU’s 1-3-1 zone defense failed to stop the Spartans’ three-point attack, and the Cats couldn’t find their own rhythm.

The Spartans, who sunk 9 of 16 three-pointers, cruised to a 73-61 victory over the Cats before a crowd of 5,743 at Welsh-Ryan Arena.

It was NU’s ninth loss to Michigan State in 10 meetings.

“I thought for 34 minutes, we played as good as we can play,” Michigan State coach Tom Izzo said.

Izzo worried slightly in the game’s final four minutes, watching his squad let a 20-point lead dwindle to just seven. But once the Spartans started draining their free throws, the Michigan State coach didn’t have to fret.

Michigan State built its 20-point advantage on the shooting of Maurice Ager and Chris Hill. Ager scored 24 points — 22 in the first half — and was a perfect 6 for 6 from beyond the arc.

“Any guy out there, on their team or our team probably can do that kind of thing on certain nights,” NU coach Bill Carmody said. “And tonight was certainly (Ager’s) night.

But it was Hill, a junior guard, who set the tone early, leading the Spartans to a game-opening 11-0 run. Hill sunk three treys before NU even got on the board and finished with 17 points on 6-of-9 shooting.

The Cats, meanwhile, didn’t score a point until four minutes into the game. They did pull to within two, 13-11, midway through the half, but couldn’t get any closer.

The Spartans, however, had no problem with their intensity level, shooting 67 percent from the field in the first half and building a 42-25 lead by intermission. The Cats’ zone, which worked so well in victories over Iowa and Illinois, proved ineffective against Michigan State.

“As soon as we got out there, we had a hand in their face,” NU guard Jitim Young said. “And they just banged the shots.”

Young said the Cats couldn’t rotate their zone fast enough to guard the Spartans’ shooters.

“They weren’t really thinking when we were playing the zone,” Young said. “It was like they were catching the ball and shooting.”

NU switched to a man-to-man defense after halftime, which helped them outscore Michigan State 36-31 in the game’s final 20 minutes.

One bright spot for the Cats was the return of sophomore Vedran Vukusic to the starting lineup. He didn’t play against Indiana on Saturday because of a hyperextended knee suffered last week against Illinois. Vukusic contributed 13 points and four rebounds.

But not even his return boosted the Cats.

“We didn’t come out with energy tonight,” Parker said.