EAST LANSING, Mich. — With 18 seconds left in Michigan’s 82-72 win over No. 4 Michigan State on Saturday afternoon, Moritz Wagner picked up his fifth foul. He proceeded to celebrate with his teammates on the bench as the Breslin Center crowd responded with some choice words for the junior forward from Berlin, Germany.

When you’re the villain–as Wagner has been for the last two years in East Lansing–a grand exit is the sweetest reward of them all.

Wagner was the difference-maker for the Wolverines in their lone regular-season matchup with MSU, finishing with a career-high 27 points on 8-of-13 shooting, going 3-of-4 from 3-point range and making all eight of his free throw attempts. He may not understand the Michigan-Michigan State rivalry like a native Michigander, but after three straight big games against the Spartans, he’s figured out enough to make it work by now.

“This game means so much for all the Michigan family out there,” Wagner said postgame. “Being from Germany, it’s a little different, but for these people, you just want to play your heart out.”

If this supposedly all-time talented Michigan State team has a true weakness, it’s a player like Wagner that can expose it. A stretch power forward that can score both inside and out can give any team in America problems, but Ohio State’s Keita Bates-Diop’s performance last Sunday means two of MSU’s three losses have effectively come down to their inability to guard at that position.

It’s not exactly Nick Ward’s fault. Or Jaren Jackson Jr.’s. But for a team whose defense was a brick wall during non-conference play, Big Ten play has definitely poked some holes in the facade.

“We went into the game with three, four different goals,” MSU head coach Tom Izzo said following his team’s second loss in three games. “One was guarding the ball screen, we failed miserably on that. One was turning the ball over. [They] had 26 points off of turnovers.”

Right now, after three straight subpar performances, it’s easy to say the sky is falling for MSU. Defensively, they’re not able to get stops at key times. The second half against Michigan was stagnant and unfocused offensively. While the Spartans’ turnover percentage is still down from last year, they still struggle with giving the ball away. That showed in Saturday’s loss, where MSU turned the ball over 18 times to Michigan’s seven.

With both teams in the bonus early in both halves, it had a much larger effect on MSU down low despite having more depth. Nick Ward sat for long stretches in both halves after ending up with four fouls, three of them on offense. Jaren Jackson Jr. had one of his best offensive performances of the year in the first half — getting to the free throw line almost at will during the first half — but he also ended the game with four fouls.

“When you take Nick out of there, we’re not as good offensively down there,” Izzo said. “So you can get the Nick controversy out of your mind. It wasn’t Nick’s fault; it was our guards. Our guards did not get over those screens.”

So much discussion surrounding Ward’s play back at the start of last month was about ball-screen defense, and after taking a lot of heat from Izzo, he turned his own game around.

It may be Cassius Winston’s turn to do the same thing. He guarded Michigan point guard Zavier Simpson for large stretches, and when Wagner and Simpson ran the pick-and-roll offensively, it usually ended in points for the Wolverines. Simpson finished with 16 points on 5-of-9 shooting and was able to get to the free throw line fairly regularly as well.

Despite knowing that a lot of what’s going wrong right now for MSU seems like correctable mistakes, it still is time to temper expectations. Yes, Izzo’s team plays their best basketball later in the season. Yes, this team still has top-end talent as good as anyone’s in college basketball this year. But what could hurt them come March is a high-end performance from their opposition’s best player — and in March, it only takes one game to derail a team’s title hopes.

Grayson Allen did it back in Chicago at the start of the year.

Bates-Diop was a thorn in the Spartans’ side last Sunday.

And now Wagner’s performance in hostile territory at the Breslin Center Saturday afternoon shows a bit of a blueprint for beating MSU in 2018: make sure your star plays his butt off, hope for MSU to get careless with the ball and have your team display enough grit to cut down Spartan scoring runs dead in their tracks.

A rivalry win for the Wolverines here tells us just as much about John Beilein’s team as it does the Spartans: they’ll be a tough team to knock out come tournament time. For as much as Michigan State shot themselves in the foot, Michigan won this game with defense as much as they won it with Wagner’s dazzling performance.

That said, MSU is at a crucial juncture in their season, and quite a few questions will be sent their way over the six-day break they now face before a Friday night home clash with Indiana. Izzo’s group is still young and immensely talented, but even for all the losing they did last year, they still have not had a stretch like the last two weeks, where they’ve been ranked as highly as the No. 1 spot in the Associated Press poll and have had the college basketball world lay heaps of praise on them.

If nothing else, this proves that the margins at the top are still razor-thin, even when your team has the ability to run any of its opponents out of the building on the right day. This performance against Michigan may be unrecognizable come tournament time, where Izzo’s teams so often manage to come up with the goods when it counts. For now, they’ll have to wait until the Big Ten tournament to get a chance at matching up with Wagner one last time.