EVANSTON Ill. — Iowa quarterback Spencer Petras threw for four yards on 2-of-4 passing on the first three drives of Saturday night’s 17-12 Iowa win over Northwestern at Ryan Field.

Then, before the Hawkeyes began their fourth drive of the contest, Petras’ night game to a close with just over two minutes remaining in the first quarter.

Citing a shoulder injury Petras sustained last week in Madison against Wisconsin, head coach Kirk Ferentz said the decision to pull Petras was a consensus among the coaching staff. Ferentz said Petras wasn’t throwing with the same “zip” as usual in pregame warmups and the first couple drives of game action.

Enter Alex Padilla.

Padilla, after playing only limited minutes during the previous two seasons, was thrust into action in a scoreless tie at Ryan Field. But the sophomore from Greenwood Village, Colorado, looked anything but flustered.

On his first two plays under center, Padilla completed passes of 2 and 17 yards to tight end Sam LaPorta and wide receiver Keegan Johnson.

Padilla continued his hot start, leading the Hawkeyes to the end zone on his first two possessions as the signal caller and heading to the halftime locker room with a 14-3 lead. The two-touchdown half equaled Iowa’s output in the last two games combined.

Padilla completed 6-0f-9 passes for 75 yards on those drives. Padilla said his steady start helped settle the nerves and give him confidence for the rest of his play.

“It was definitely a confidence boost,” Padilla said of his first touchdown drive. “We were struggling a little bit on the first couple drives, but I think being able to put together a touchdown drive there was a really crucial part of the game. Always happy to have touchdowns.”

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Although Ferentz said Petras had been making good progress all week with the shoulder issue and there was no question Petras would start the game, Padilla did get some reps with the first-team offense in practice as Petras rehabbed his shoulder.

“We had an idea that he was banged up through practice,” Hawkeye running back Tyler Goodson said of Petras. “Especially at the beginning of the week… We had an idea that he had something going on with his shoulder. I don’t know exactly what it was.

“We just had to get Alex prepared and be ready for any type of situation,” Goodson added. “We knew it was a possibility that he could come into today’s game and go in and produce and that’s what he did.”

Padilla said that he always prepares like he’s going to start, and that hard work paid dividends in his first meaningful action as a Hawkeye.

Defensive back Dane Belton, who recorded two interceptions Saturday night — including the game-sealing pick with 1:51 to thwart a potential game-winning Northwestern drive — said Padilla’s work ethic gave the team reason to have faith in the second-year player.

“He’s a hard worker,” Belton said of Padilla. “You can always trust him to get extra reps after, before practice, or on our off day. He’s one of the guys that you can trust to get the job done.”

Padilla sure got the job done in his first extended opportunity as a Hawkeye.

Padilla finished the night 18-of-28 passing for 172 yards and a 67.9 passer rating — the third-highest mark of the season for an Iowa quarterback.

Who will start next week if Petras is back to 100 percent?

“We’ll look at the film and see what we think,” Ferentz said.