Northwestern overcame a 17-0 deficit on Saturday to hand host Iowa a 21-20 defeat in Week 2. Iowa drops to 0-2 for the first time since 2000.

Northwestern’s Jesse Brown put the Wildcats ahead on a 2-yard rushing touchdown with 6:05 left in the third quarter, the game-deciding score and the final points of the contest.

“(Northwestern) played a better second half than we did, and that was really the story of the game,” Iowa coach Kirk Ferentz said. “You’ve got to play the full 60 minutes, and at the end of the game, all the critical areas — running the football, third-down conversions, the turnover rate — obviously, are going to be important in deciding the football game. We did a good job of that in the first half, not so much in the second half. They finished the game and we weren’t able to. That’s kind of where we’re at right now.”

This was Northwestern’s third straight victory at Iowa. In each of the last three games at Iowa in the series, the Hawkeyes had a halftime lead.

Here’s the Week 2 report card for Iowa:

Offense: D

For the second straight week, Iowa scored just 20 points. Iowa raced to a 17-0 lead at the end of the first quarter but could only muster 3 points (in the second quarter) the rest of the way.

The Hawkeyes defense held up its end in the fourth quarter, but Iowa couldn’t muster up anything offensively to engineer a comeback.

It was a rough outing for quarterback Spencer Petras, who finished with 216 yards, 1 touchdown and 3 interceptions.

Petras completed 9 of his first 11 passes and threw his first career touchdown pass on an acrobatic 7-yard reception by Brandon Smith early in the first quarter.

“That’s the kind of guy he is,” Petras said of Smith. “He’s competitive, aggressive, and when the ball’s in the air, he’s going to get it.”

However, Petras went on to finish 26-of-50 on his passes, with all 3 of his interceptions came during Iowa’s scoreless second half. Iowa amassed just 104 yards after halftime. Two of Petras’ 3 interceptions came on targets to tight end Sam LaPorta.

LaPorta had 6 receptions for 46 yards. Iowa receiver Ihmir Smith-Marsette finished with 7 receptions for 84 yards but couldn’t shake free in the second half.

Petras credited the Northwestern defense for pass coverage.

“They disguised things really well,” Petras said. “Credit to Northwestern today. They played really well. They got us.”

Tyler Goodson scored Iowa’s other touchdown on a 15-yard run midway through the first quarter.

Ferentz lamented the inability to create offensive balance. While Petras and the passing attack were limited, the rushing game only had 23 carries for 77 yards.

“If you look historically at those kinds of numbers, the outcome probably wasn’t very good,” Ferentz said. “We didn’t run the ball effectively enough today (23 for 77 yards). Certainly hit a couple of runs on them, but with consistency, not enough. That’s something we have to address, because we don’t want to play that way. I’ll go on record saying that. We don’t want to play that way. Looking for a lot more balance than that.”

Defense: C

It was quite the mixed bag for the Iowa defense. Iowa shut out Northwestern in the first quarter and fourth quarter, while giving up all 21 points in the second quarter and third quarter.

Northwestern went 10-of-19 on third down conversions and 2-of-2 on fourth down conversions.

Middle linebacker Seth Benson, who led Iowa with 13 tackles, took accountability for the run defense’s struggles in the second quarter. Both of Northwestern’s touchdowns in the second quarter came on runs: A 3-yarder by Kyric McGowan and a 1-yarder by Brown.

Brown’s other rushing touchdown in the third quarter capped off the game’s scoring.

“They run the ball, are a good running team,” Benson said. “That was our goal, to stop the run. Obviously we didn’t go that good enough in the second quarter. We’ve got to be tighter on our fits, be better in our communication, and that starts with me.”

Overall, the run defense allowed 2.4 yards per carry and 143 yards against Northwestern, which are improvements from last week against Purdue. Iowa forced an interception (by Jack Koerner) and recovered two fumbles (by Terry Roberts and Zach Van Valkenburg). This is the first time since against Nebraska in 2012 that Iowa lost a game in which it recovered at least 2 fumbles.

The passing defense held Northwestern quarterback Peyton Ramsey to 130 passing yards, no touchdowns, and an interception.

Defensive tackle Daviyon Nixon recorded 11 tackles and 1.5 sacks. Nick Niemann added 10 tackles.

Nixon is disappointed with the defense’s performance during the first two weeks of the season. The defense recovered for the final 21 minutes of the game on Saturday but by then it was already too late because of the offense’s shortcomings.

“It’s basically the same thing (through) two weeks,” Nixon, said. “We’ve got to finish. Iowa is a big team on finishing, and we just haven’t been able to do that these last two weeks. We’ve got to get back to playing Iowa football and finishing out strong.”

Special teams: B

Iowa kicker Keith Duncan converted both of his field goals and extra point attempts. Duncan made a 22-yard field goal in the first quarter and a 47-yarder in the second quarter. Iowa punter Tory Taylor averaged 49 yards on his four kicks, with a long of 58.

The Iowa return game was modest, as Smith-Marsette picked up 33 yards on his lone kickoff return and Charlie Jones only tallied 8 yards on his 2 punt returns. Iowa held McGowan in check, allowing only 18 yards on his lone kickoff return and stopping him for n 8-yard loss on the only punt return.

Iowa will host Michigan State in Week 3 on Nov. 7 (11 a.m. CT, ESPN).