IOWA CITY, Iowa-Northwestern trailed Iowa just 12-7 at the half on Homecoming Saturday at Kinnick Stadium. Even though the offense managed just 82 total yards, a pick-6 by Theran Johnson kept the Wildcats within striking distance.

Then the roof caved in on them in a brutal third quarter that turned a tight, low-scoring game into an embarrassing rout. In 15 minutes, Iowa blitzed Northwestern with four straight touchdowns, all while outgaining the Wildcats 167-33. The fourth quarter was a mere formality as the Hawkeyes coasted to a 40-14 victory.

Adding insult to injury, it was former Wildcat quarterback Brendan Sullivan who led the onslaught. He replaced Cade McNamara after the starter threw an interception in the second quarter and ignited the sleepy Iowa offense. He finished a very efficient 9-for-14 passing for 79 yards in nearly three quarters of play and added 41 yards and a touchdown on the ground.

The man who beat Sullivan out in camp last spring, Jack Lausch, once again struggled leading the anemic Wildcat offense. He was 10-of-19 for just 62 yards through the air and threw two interceptions. He also was sacked for a safety.

Lausch was pulled late in the game but head coach David Braun maintained that the offense’s problems go far beyond their signal caller.

“Our only issue is not the quarterback,” he said.

What are the issues? “Everywhere, the entire football team.”

The Wildcats wound up with 14 points in the game, but the offense was shut out. The defense got one TD on Johnson’s interception, and the special teams claimed the other on a 72-yard punt return by freshman walkon Drew Wagner in the fourth quarter, when the game had long been decided.

Northwestern hasn’t scored a touchdown since the Maryland game two weeks ago and has managed just a field goal in its last eight quarters.

It was Iowa’s fourth straight win in the series, their longest streak since 1991-94, just before the Wildcats’ historic Rose Bowl run in 1995. It was Northwestern’s most lopsided loss against the Hawkeyes since a 40-10 beatdown in 2015.

Northwestern’s offense finished with just 163 yards, their second lowest total of the season. They have produced 300 or more yards just once in five Big Ten games.

But, as Braun pointed out, all three phases contributed to the third-quarter collapse.

The defense that had been so stout in the first half suddenly started giving up explosive plays. Sullivan hit Johnny Pascuzzi for a 40-yard pass on their first touchdown drive of the period. Then, the special teams allowed an 85-yard punt return by Kaden Wetjen. The defense gave up 41- and 25-yard touchdown runs by Kaleb Johnson on which it looked like the Wildcats weren’t too interested in tackling the Big Ten rushing leader.

Theran Johnson attributed the defensive collapse to poor tackling, pointing out that he missed one himself on one of Kaleb Johnson touchdown runs.

"I feel like we had the gameplan, just a lot of missed tackles,” he said.

And the offense did its part by continuing what it started in the first half: they produced four punts and an interception in their five possessions of the quarter.

It was a total team effort. But not the kind that Braun had envisioned.

“Poor performance in all three phases,” said Braun. “We're going to find out a lot about our team as we transition into the next two days and back to work as we prepare for Purdue.

"That was an embarrassing performance, embarrassing loss, embarrassing second half, and we're going to have to respond."