In a cracking Sunday afternoon qualifying final, Cleary was sin-binned for collecting Hugo Savala's leg before breaking a 12-12 deadlock with a late field goal at CommBank Stadium.
Adding to the drama, the Penrith No.7 also injured his foot in the process of landing the dropkick, seeking the attention of trainers before opting out of taking the conversion attempt after Brian To'o's late try.
The result means the Roosters will host Cronulla in a do-or-die semi-final on Saturday night, while Penrith are one win away from their sixth grand final in seven years.
But all eyes will be on the NRL's charge sheet on Monday, with Cleary anxiously awaiting what sanction he will face for crashing into Savala's leg after the Roosters player kicked in the first half.
The Panthers star immediately gave a worried look, before referee Gerard Sutton told him his action had "force", was "very dangerous" and "carried a high risk of injury".
"He's just trying to make a play. He's probably thinking the right thing there," coach Ivan Cleary said.Â
"The angle was wrong and under the current rules it's probably the right call.
"The same thing happened to him down the other end under the posts early in the game, but anyway."
If Nathan Cleary was to receive a grade-two dangerous contact charge on Monday, the game's best player would be facing a ban from the preliminary final with an early plea.
Should he elect to challenge the charge, he would risk being rubbed out of the grand final if found guilty.
A grade-one charge would only attract a fine for Cleary, and prove a massive boost in Penrith's bid for a fifth premiership of their dynasty.
Asked if he felt the halfback deserved a ban over the contact, Ivan Cleary said: "God no. Of course not.
"He just got the wrong angle. It's one of those rules that has come in over the past couple of years and sometimes in the heat of the battle you forget.
"He's not injured. It's just a black-and-white thing they have brought in."
Manly's Josh Aloiai and South Sydney's Jacob Host were handed grade-two charges by the match review committee for collecting the outstretched legs of kickers in 2024.
But Melbourne's Harry Grant did manage to have a grade-one charge for contact on Dan Atkinson overturned that year.
The Roosters failed to make use of Cleary's sin binning. Savala missed the ensuing penalty goal and was denied a try for a double movement after the break.
That was one of the few chances during a scoreless opening 32 minutes of the second half, before Cleary stepped up as the game's ultimate ice man.
Sat in the attacking line after a searching Moses Leota run, Cleary was able to slot over the one-pointer with no pressure from Roosters defenders.
"I would have liked to have put more pressure on him," Roosters coach James Tedesco said.
"But it was just a quick play-the-ball and a quick ruck."
Daly Cherry-Evans attempted to reciprocate moments later, but sprayed a shot from 20 metres out to the right before To'o's sealer under the posts.
Cleary's boot also wreaked havoc early on Sunday, with the Roosters unable to handle three of his bombs and Liam Martin leaping to score off one of his shallow cross-field kicks.
Cleary also changed the point of attack and went back inside to Dylan Edwards for the Panthers' second try, with the fullback swerving his way over to make it 12-12 after 38 minutes.
Mark Nawaqanitawase's freakish ability had kept the Roosters in the match in the first half, with two key intercepts either side of a Robert Toia try.
The Roosters winger first helped deny a Penrith try when he reached out and held onto an Isaiah Papali'i ball in the third minute.
He then gave the Roosters a 12-6 lead when he stretched out to stop a Penrith break, juggled the ball three time as he fell, got up and ran 45 metres to score.
