O'Connell threw for 271 yards and Dellinger kicked a 39-yard field goal with three seconds left Saturday as Purdue beat Northwestern 24-22 to keep its bowl hopes alive.
O'Connell, a former walk-on, made his first start after Elijah Sindelar (broken left collarbone) and Jack Plummer (broken right ankle) went down with injuries. He guided the go-ahead drive late after Wildcats kicker Charlie Kuhbander's 32-yard field goal bounced off the left upright.
David Bell made 14 catches for 115 yards and a score as the Boilermakers rallied from down 14-0 in the first quarter. Northwestern lost its seventh straight, while Purdue beat the Wildcats for the first time since 2010 after losing five in a row.
O'Connell quarterbacked the winning drive last week against Nebraska, and he came through again.
"It wasn't a pretty game, and we had some moments where we looked really bad," Purdue coach Jeff Brohm said. "But we hung in there, and that has kind of been the sign of our team."
Northwestern (1-8, 0-7 Big Ten) scored more points than in its four previous games combined, as receiver-turned-tailback Kyric McGowan rushed for 146 yards and a score.
O'Connell struggled in the first half but helped Purdue (4-6, 3-4 Big Ten) outscore Northwestern 17-6 after halftime. The Wildcats committed two pass interference penalties on the final drive to keep Purdue in it, and Dellinger knocked through the game-winner into gusting wind.
"I had a good feeling we were gonna at least get a chance at it," Dellinger said. "It felt really good off my foot, and it looked pretty dead straight almost all the way there, so I felt good about it."
McGowan lined up in the backfield and burst up the middle for a 79-yard touchdown on Northwestern's second play from scrimmage. Aidan Smith found a diving Jace James from 16 yards out to put the Wildcats up 14-0 on the next drive, and Northwestern added a safety.
Purdue running back King Doerue bounced outside for a 12-yard score in the second quarter. Then O'Connell floated touchdown passes over the defense to David Bell and Amad Anderson in the third. The Wildcats retook the lead when Smith connected with Riley Lees in the fourth, but they couldn't close it out.
"Probably the best response I've seen from our team all year responding from adversity," Northwestern coach Pat Fitzgerald said. "We got it back, we put together a great drive and then the last four minutes of the game the difference was discipline."
Purdue: The Boilermakers have a tough road remaining with games at Wisconsin and at home against Indiana, but they can still qualify for a bowl game.
Northwestern: A season marked by lifeless offense will end in a last-place finish in the Big Ten West. It'll be the Wildcats' worst season since at least 2006, Fitzgerald's first season at the helm.
Northwestern called timeout before Dellinger's go-ahead field goal in an attempt to ice him. Dellinger was just fine with that.
"I think it helps, honestly," Dellinger said. "It gives me a chance to catch my breath. I guess I probably shouldn't say that if any other coach is watching the replay later."
O'Connell made his first career start close to home. He graduated from Stevenson High School in Lincolnshire, Illinois, and had family waiting for him outside Purdue's locker room after the game.
"Just had a lot of people . who make me reflect and realize how grateful I am and how many people poured into me when things weren't going my way early in my career," O'Connell said. "When you have that, you really feel like you can do anything."
Purdue: Off next week before a trip to Wisconsin on Nov. 23.
Northwestern: Hosts Massachusetts in a break from Big Ten play.
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