Ugly wins are still wins, just ask Michigan after its 20-13 verdict Saturday over Rutgers, which was a 3-touchdown underdog.

The “Fire Harbaugh” tweets were rampant, but the Wolverines still emerged with a victory during perhaps their worst appearance of the season.

“We celebrate all wins,” UM coach Jim Harbaugh said after the game, following with it’s “onward to Wisconsin next week.”

Michigan punted 5 times vs. Rutgers; it only punted 6 times during its 3 previous contests this year.

Jim Harbaugh shouldn’t be fired. Michigan is still undefeated as it looks toward its first major test of the season — next weekend’s road trip to Madison to face Wisconsin, which was blown-out 41-13 by Notre Dame.

Whether it was a blowout or a slim edge, the Wolverines still remain unblemished. It’s difficult to criticize a team that did what it had to do in order to get on the positive side of the scoreboard, but there is plenty to dissect following the Wolverines’ toe-stubbing win over Rutgers.

Here are the grades from Saturday’s meet-up in Ann Arbor.

Offense: C-

Blake Corum entered Saturday as one of the hottest running backs in all of college football — but that was before he was shut down by the Scarlet Knights, who surrendered a season-low 68 yards to Michigan’s Mike Hart-hopeful speedster. Corum wasn’t a factor and his O-line didn’t give him much of a chance to break off big plays, like he had done through the first 3 weeks of the season.

Hassan Haskins scored 1- and 4-yard touchdowns in the first quarter, appearing to put Michigan on the clear path to a lopsided win. However, Haskins was held at bay for the remainder of the afternoon, finishing with 12 carries for 41 yards. Previous to Saturday, the Wolverines had routinely put up large numbers against the opposition. It wasn’t a flash-in-the-pan, as UM still holds one of the better backfields in the nation, but it was a wake-up call for a team that had steamrolled through defenses via the ground game.

When gauged against the previous 3 games, the Michigan offense did not pass the eye-test and looked rather lethargic with just 275 total yards.

Defense: D+

The Wolverines’ defense looked pretty tough through 3 weeks before meeting their first conference opponent in Rutgers, which put up a season-high 352 yards against Michigan.

Ruling the 3rd quarter, Rutgers had 7 first d0wns and scored an odds-altering 14-yard touchdown on a pass from QB Noah Verdal to Aaron Young, which cut into Michigan’s lead, 20-10 in favor of UM.

Special teams: D

Entering Saturday, Jake Moody was 3-3 when kicking field goals. On Saturday, he was 2-for-3 with a long of 32 yards. The Wolverines didn’t wow with big returns — AJ Henning had a 29-yard return that was the highlight of the day — and Jake Robbins was forced to punt 5 times — nearly as much as he had punted during the first 3 games (6).

It wasn’t a pretty win for Michigan but it was still a win for Harbaugh, who has his Wolverines at 4-0 in advance of their meeting with Wisconsin, which will be a true test for the Wolverines next weekend in Madison.