It had to be perfect.

Ryan Browne stood in the pocket and saw that he had running back Devin Mockobee with about two yards of space on his man, streaking for the corner of the end zone.

The freshman quarterback's team was down 40-35, with the time left on the clock beginning with a zero – 51 seconds.

That's when he unfurled a pass that looped, high and slow, on its way into Mockobee's arms, to be wrapped up and hugged as the junior back fell down for 6 points with his defender close enough to whisper to him.

That throw was perfect, and then so was the onside kick that made it possible. That football, dribbling through a scrum of opposing special teamers and ending up in the unlikely hands of Leland Smith.

It was all, somehow, going perfectly for Purdue.

Until it wasn't.

Junior quarterback and newfound Big Ten sensation Luke Altmeyer eclipsed 300 yards passing on the next drive with strikes that gave No. 23 Illinois a tying field goal. Then it was overtime in a game with 72 points scored after the halftime whistle, spinning deliriously on.

Altmeyer struck again, a 25-yard touchdown pass to the back of the end zone. Again, Purdue answered, Devin Mockobee stomping 22 yards and Purdue scoring the next play ... it was still going perfectly, again, until it wasn't.

Because on the next play, with coach Ryan Walters deciding he'd had enough of his Boilermakers' balancing act, Purdue was far from perfect, and it lost what nevertheless was an extraterrestrial performance for a team that seemed hopeless a week ago.

Purdue went for 2. Browne stood in the pocket, his team down 50-49, ready to throw his 27th pass. But he never threw it.

Illini coach Bret Bielema set him up. “Our offense is gonna score, we’re gonna go for 1,” he told his defense. “But if they score, they’re gonna go for 2.”

He was right, and called the perfect play. He dialed up linebacker Dylan Rosiek, who bull rushed Browne right up the middle.

The freshman pivoted, spun, then whirled and scrambled back, back, back. He began a last-gasp swing from the pocket, but was finally wrangled, and Purdue, that slippery underdog, was wrangled with him

"Giving everything I can to win the game," Browne said of his performance, and sniffed. His eyes were pink.

The Boilers now find themselves at 1-5 and winless, in three tries, in the Big Ten. Illinois will continue on after its brush with disaster at 5-1, a record inverted to Purdue's like the halves of the two teams' Saturday evening.

A hapless Purdue team entered the game. Illinois scored on five of its first six drives, and Purdue brought a six-quarter touchdown-less streak that reached back into September to halftime.

The Illini offense hummed and sang; Altmeyer was surgical, hitting wide receivers and running backs and watching them compile 215 receiving yards.

"Especially in the first half, we didn't execute like we wanted to," Heldt, a rush end, said. "We gotta be better."

Then he turned to three offensive teammates beside him – the ones he worked with to bring Purdue back as an ordinary second half of an ordinary blowout became anything but.

Heldt brought his team to within 10 points when he collected a fumble and rumbled across the goal line halfway into the third quarter. Then Purdue's defense put its foot down on the ensuing drive, defending an 8-yard pass on fourth-and-2.

Those were the only two drives of the second half and overtime that didn't end in scores for the Illini. But it was enough – for a time, anyway.

That's because Purdue's offense came alive thereafter, with Ryan Walters calling plays on the other side of the clipboard for the first time in his career.

"I felt like that was gonna give our team the best chance to win," Walters said of his role change. "That’s my job as the head coach."

It was as if Walters had to warm up.

The Boilers threw for a comical 9 passing yards in the first 30 minutes, getting only a field goal from it. Explosive and physical, Browne played as a third running back, recording gains of 12, 16 and 20 on his longest first-half rushing plays.

But then, somewhere, a switch flipped, and Purdue scored on every drive after halftime. Browne was a thrower, passing for gains of 53, 62 and 40. There was the serendipity of busted coverages, trick plays and a quarterback in control.

"We didn't panic," Walters said.

"I'm super proud of (Browne)," said tight end Max Klare, "because he played his ass off and gave us a chance to win that game."

Klare erupted for 133 receiving yards. Purdue’s offense finished with a staggering 511 yards, 415 of which Browne accounted for.

For weeks, through an offensive coordinator change and now a play-caller swap, it has been unclear what Purdue’s offense needed to get rolling. Saturday, it seemed to be Browne.

“We wanted to utilize Ryan’s athletic ability,” Walters said. “You add an extra half to the game by using the read plays and RPOs.”

The Boilers showed on Saturday all the little things they’ve had going for them, those things that finally seeped into the box score and created a game worth following up to the very last gasp.

“The message all week was to just come together and play for four quarters,” Heldt said. “I feel like we did that.”

But then he said the second part, the part that echoes that doomed overtime play and the 50 points surrendered on Heldt and his defensive teammates: “We just gotta execute at the end of the day, we gotta be better.”

“Would have loved to win that game,” Walters said. “You know, you pour a lot into it. And guys are fighting, fighting for you. You claw your way back when we haven’t done that this year.”

He said it with a clearing of his throat, with eyes in the distance, a head swirling with the numbness of What just happened?

Purdue hasn’t done that this year, nothing like it.

And as for what it means, just ask any Illinois fan how they felt watching the Boilermakers come back on their prized, ranked football team. They were silent for much of the third quarter, shocked at watching a Purdue team actually punch back.

No, Purdue wasn’t quite perfect, as it needed to be. But it at least showed a pulse.