Cleary resurrected the Broncos' demons with an individual masterclass similar to that which sealed the Panthers' comeback victory over Brisbane in the 2023 decider.
This time, the halfback's heroics lifted Penrith from the bottom of the ladder and breathed life into a campaign pushed to the brink by six losses in the first eight rounds.
Before a hostile Brisbane crowd on Sunday, the Panthers resembled their four-time premiership-winning selves more closely than at any point this year.
This was vintage Penrith: Uncompromisingly physical, defensively tight and steered to victory by superstar halfback Cleary.
But father and coach Ivan Cleary is not getting ahead of himself.
"Is it a turning point? I don't know," he said.
"Two weeks ago was a good game (beating the Sydney Roosters). Last week, the first half wasn't great.
"I'm obviously happy. I thought it looked like the sort of performance that we can proud of."
Nathan Cleary put up the kick for Izack Tago to score the Panthers' first try, then nailed the 40/20 kick that put them in position for Luron Patea to burst past four defenders and nab their second.
The superstar halfback then stepped inside on a shift to the left and danced past opposite man Adam Reynolds for the Panthers' third try, bringing back memories of the four-pointer that won the Panthers the 2023 grand final.
"As I scored it, Dyl (Edwards, fullback) actually came up to me and said, 'I've seen that before'," Cleary said.
"It's obviously different circumstances but it was nice.
"I hadn't been playing the way I want to and obviously with the results we've had, it's disappointing.
"But in saying that, I thought us as a group and myself individually, we're doing all the right things. Our preparation was good. It just wasn't happening on game day so we took confidence out of that."
The result was beyond doubt after a second-half double from winger Tom Jenkins, who was on the job as a disability support worker a matter of weeks ago.
For eight minutes in the first half, when the scores were locked 8-6, the Panthers did not have a single play-the-ball and were defending their line for most of that time.
But Reynolds could not inspire the Broncos to points other than an equalising penalty goal in this period as the Panthers reprised their premiership-winning goal-line defence.
The passage of defensive play ultimately laid the platform for victory; the Panthers scored on their first chance thereafter and never looked back.
As Cleary shone, Brisbane skipper Reynolds sprayed two kicks out on the full, with Jenkins scoring directly after the second of those.
"I'll put my hand up there, I obviously didn't have one of the greatest games," Reynolds said.
Reynolds insisted he had no yips facing Penrith, despite the Panthers getting the better of him in the 2021 and 2023 grand finals.
"You can write all the headlines and everything you want but there's none of that," he said.
"I turn up week after week and try and put the best performance in no matter who we play against."
The Broncos have now lost nine of their past 10 outings against the Panthers.
"It was disappointing but we'll take a fair bit out of that," said coach Michael Maguire.
"It's never nice losing like that because of the effort the players are putting in and what they're learning about how we want to play."
A corked quadriceps muscle meant Broncos forward Xavier Willison could not finish the game.
