In a chaotic final eight minutes, where the scoreline changed three times, Broncos forward Tom Flegler was ruled to have collected Sitili Tupouniua high by the NRL Bunker after James Tedesco challenged a knock-on decision in the 78th minute.
Roosters centre Adam Keighran brushed aside the club's goal-kicking woes this season to slot the match-winner after the Broncos looked to be home only moments earlier in a crazy passage of play.
Broncos coach Kevin Walters didn't blame the final call indicating he "hadn't had time to digest it yet", but pondered the thought of a similar act ever deciding a grand final.
"I don't have any grievance with it, that's the game," Walters said.
"Footy can be cruel and can also be a great game sometimes. We'll wake up tomorrow.
"I don't think we were dudded. Referees are there to adjudicate."
Brisbane were on track to deliver an upset when Roosters lock Victor Radley was penalised for attacking the legs of kicker Albert Kelly, who was attempting a field goal, to allow Selwyn Cobbo to slot a 76th-minute penalty for a 20-19 lead.
Four minutes earlier and Roosters half Sam Walker had broken an 18-18 deadlock with a field goal.
Roosters coach Trent Robinson defended the Radley challenge on Kelly after his return match against the Broncos following a five-match ban when the teams met in May ended with him being placed on report.
"If someone thinks that's an emotional play, I'd be surprised," Robinson said.
"That's a guy who's doing everything he can to charge down the ball. That's very different, I wouldn't like to align the stuff that happened against Brisbane last time to this time," he said, referring to the Roosters round 11 loss to the Broncos.
"He's just disappointed he let them back into the game."
For the Roosters, Tedesco was enormous for the Tricolours to finish with 216 metres from 30 carries in a roaming captain’s knock in the No.1 jersey.
Robinson also paid tribute to club stalwarts Isaac Liu and Siosiua Tauekiaho in the engine room with Jared Waerea-Hargreaves (rested) and Angus Crichton (suspension) missing.
"It was a wild game there, there was big range in quality from us and them," Robinson said.
"There were players playing well and players who were struggling during the game.
"That's why it ended exciting at the end. We're in the fight. We understand where we're at. We know we want to improve but we believe in our team and the jersey we play for."
Both sides traded three tries each for that 18-18 scoreline in greasy conditions in Brisbane.
The see-sawing contest began in the unlikeliest of ways with Broncos behemoth Payne Haas opening the scoring at one end before Isaac Liu dived over in a similar play five minutes later.
The Broncos were lucky to not be temporarily down a man in the 29th minute when David Mead ripped the ball from Tedesco on the attack after the livewire fullback made a 40-metre bust.
Mead wasn't as lucky defensively moments later, however, when Tedesco sent former Bronco Dale Copley over the line with a deft kick into the in-goal.
The Broncos liked their chances in a mid-air contest between Xavier Coates and Daniel Tupou with the returning winger setting up the side's second by batting the ball back for Jordan Riki to cross in the corner.
Not to be outdone, Tupou looked to have crossed before half-time but a last-ditch effort from Tyson Gamble forced him into touch.
Anthony Milford made his way back onto the field for the first time in over two months with the Rabbitohs-bound playmaker replacing Gamble midway through the second half.
Gamble struggled with a suspected fractured hand moments before leaving the field while the Broncos also lost rookie Xavier Willison to a knee injury. Walters said Gamble would have scans Saturday.
The Broncos hit the front midway through the second half with Flegler producing a wonderful piece of play - stepping off both feet - to keep the ball alive on the last tackle for Albert Kelly to cross under the posts.
However, the Roosters came up with a power-play of their own to level the scores two minutes later with Tauekiaho getting past Danny Levi to set up Tedesco under the sticks and set up the grandstand finish.
Story first published on NRL.com