INDIANAPOLIS — The Michigan Wolverines needed an affirming victory after clearing their defining hurdle of the season with a commanding win over Ohio State.

And late Saturday night, in a chilly Lucas Oil Stadium in front of the largest crowd in the history of the Big Ten championship game, Michigan followed through with a 42-3 rout over Iowa for the conference title, cementing a spot for the Wolverines in their first College Football Playoff.

The Big Ten championship game was the finale of one of the most consequential days of the college football season, with teams battling for one of four semifinal spots in the playoff. The selections, made by the consensus of a committee, will be announced on Sunday. No. 5 Oklahoma State fell to Baylor in the Big 12 championship, effectively rendering its claim void. Alabama, ranked third by the committee going into the Southeastern Conference championship game, handed No. 1 Georgia a humbling loss in what might have been a playoff preview. No. 4 Cincinnati easily beat Houston for the American Athletic Conference title. That left No. 2 Michigan, a program mired in a yearslong cycle of getting far, but not far enough, yet energized by its win over the Buckeyes and its chances for a national title.

The Wolverines (12-1) thwarted every Hawkeyes attempt at reaching the end zone Saturday with a bend-but-don’t-break approach on defense, and Iowa (10-3) finished with a thud. The Hawkeyes lost two straight games to Purdue and Wisconsin at the end of October but went undefeated in November to earn their first conference championship appearance since 2015 (in 2004, Iowa shared the conference title crown with Michigan). But an anemic offense and missed opportunities proved their undoing against the Wolverines.

Under Coach Jim Harbaugh, Michigan had grown accustomed to underachieving disguised by an ability to mow through its nonconference schedule and to beat up on lesser Big Ten opponents. But far too often — at least by the standards of the high stakes world of marquee college football — it would lose the big games. Harbaugh’s first season in Ann Arbor included a loss to then No. 7 Michigan State in 2015. The Wolverines were blown out by Penn State (then No. 2) in 2017 and lost by a touchdown to the Nittany Lions in 2019.

And of course, before this season, Michigan was 0-6 against Ohio State during Harbaugh’s tenure.

Last year, the Wolverines went 2-4 in a season that could have put an irreparable dent in Harbaugh’s legacy. Michigan’s notoriously vaunted defense looked nothing of the sort. The Wolverines lost every one of their home games. A coronavirus outbreak ended their season before they could face the Buckeyes.

And yet Michigan extended Harbaugh in January (though he took a significant pay cut) and he revamped the program, possibly detecting the thinning patience among the Wolverines’ fans after last year’s flop. He brought in six new coaches for his staff, including a new defensive coordinator.

The result was a defense ranked among the best in the country this season. Michigan allowed 319 yards a game and 4.78 yards per play before rolling past Iowa.

The Wolverines’ defense held Iowa to 104 rushing yards on 33 attempts. Michigan got to the quarterback once, on a 10-yard sack by Aidan Hutchinson, the Big Ten’s Defensive Player of the Year whom many pundits believe should be a Heisman Trophy finalist.

“We defied all expectations. Nobody thought we could do this,” Hutchinson said after the game. He took home the game’s most valuable player award. He added: “And we did it in very dominant fashion.”

Iowa won the coin toss and unsurprisingly sent its defense, which had been its strength all season, out first. The decision seemed to give the underdog Hawkeyes the jump start they needed to capture the game’s early momentum. After forcing a Michigan three-and-out, the Hawkeyes quickly marched down the field, only to have their promising drive undone by a missed 33-yard field goal.

Michigan scored easily on the next drive. Running back Blake Corum took a handoff 67 yards for the touchdown, using a gaping hole created by the Wolverines’ offensive line, a shifty sidestep and a downfield block by backup quarterback J.J. McCarthy surprisingly close to the neon orange pylon. It was the longest rush the Hawkeyes have allowed this year.

It took the Wolverines a single play to silence the Hawkeyes fans in the sold out crowd at Lucas Oil Stadium once more. In a trick play, running back Donovan Edwards took a backward pass from quarterback Cade McNamara and hit a wide open Roman Wilson in stride for a 75-yard score.

The Hawkeyes responded by again strutting down the field with ease but could not capitalize on their goal-to-go opportunity, settling for another field goal.

It was beginning to look like the game was rapidly slipping away from the Hawkeyes. Michigan’s next dive started with a reverse that receiver A.J. Henning took 29 yards. But two plays later, quarterback Cade McNamara’s heaved a pass behind tight end Erick All, and Iowa linebacker Jack Campbell was waiting for it, grabbing the game’s first takeaway.

Michigan finally found its run game in the third quarter building a methodical drive that opened up Iowa’s defense for a big play. Luke Schoonmaker, a tight end, leapt into the air to bring down a 27-yard catch in coverage, which made way for running back Hassan Haskins, who got a good block on the right edge, to walk into the end zone and seemingly put the game out of reach at 21-3.

Iowa replaced quarterback Spencer Petras on the Hawkeyes’ second drive of the third quarter, and backup Alex Padilla guided Iowa down the field in a time-consuming drive that ended with a resounding fourth-down stop by the Michigan defense.

The Wolverines blocked a punt, used a flea-flicker and punched the ball in from the one-yard line to add 21 cushion points in the fourth quarter.

Many in the stadium’s crowd of over 67,000 fans, as booming and energized as they were in the opening minutes of the game, had quieted by the fourth quarter. The others, wrapped in their team’s maize and blue colors, roared as Harbaugh was shown on the stadium’s screens jumping into his players’ arms.

“There’s no team I love more than this team,” Harbaugh said after the game. He added: “It’s just the way they approach it. They give it their best every day. Just that simple thing. Nobody ever thinks it's that simple, but it’s that simple.”