Roosters 24 Broncos 22
Latrell Mitchell spared Blake Ferguson's blushes - and his own - engineering a stunning Roosters recovery that has the tricolours on the cusp of their first grand final in four years after a wild win over the Broncos.
Just four minutes after the otherwise outstanding Ferguson bizarrely batted a game-changing Benji Marshall 40-20 attempt back infield, allowing Corey Oates to stroll over for his second try and give Brisbane their first lead of the night, Mitchell's swerving effort pushed the Roosters to the brink of another decider.
It capped a crazy night at Allianz Stadium after the Roosters - who bolted to a 14-point lead inside the first half hour - scrambled home 24-22 on Friday night to condemn Brisbane to sudden-death football for the rest of September.
The depleted Broncos fought back to take an improbable lead inside the final 10 minutes after tries to Ben Hunt and Oates within two minutes, but Mitchell stood up opposite number James Roberts to have the final say.
The Broncos, perhaps with the help of returning skipper Darius Boyd, will face the winner of the Sea Eagles-Panthers clash at Suncorp Stadium next week in an elimination final.
A stunned Roosters coach Trent Robinson sat partially in disbelief, maybe bewilderment, in his coaching box after Roberts unluckily toed the ball over the dead ball line on the game's final play without an opponent near him.
It was the fitting end to a bizarre match in which the Roosters looked in complete control minutes before half-time, but conspired to throw away the match thereafter.
Mitchell fumbled the ball and couldn't re-grip it when on the brink of padding the Roosters' second-half lead to 14 - and it looked like it would come back to bite him as Hunt kicked for himself and outsprinted Michael Gordon to start a late rally.
Oates' second, when Ferguson miraculously kept Marshall's kick in play with not another Rooster in sight, set up a grandstand finish but the Broncos' lead only lasted four minutes thanks to 20-year-old Mitchell's heroics.
It was a relief for the hot-and-cold tricolours, but was it enough to put the shudders through red-hot premiership favourites Melbourne? Hardly.
Wayne Bennett braved the cold and forfeited the comfort of the coaching box to park his right-hand men in the stands - and wouldn't have been warmed by the opening exchanges as his undermanned side struggled to match it with the quick-starting Roosters.
Despite struggling past also-rans in the Tigers and Titans in the last month of the season, the Roosters torched Brisbane in the opening quarter, laying on tries through representative back-rowers Aidan Guerra and Boyd Cordner against a static Broncos defensive line.
Michael Gordon's penalty goal extended their buffer to 14, but the Jekyll and Hyde Roosters resurfaced in the minutes prior to the break as Marshall's inch-perfect grubber was grounded by a flying Roberts.
Keary ghosted around the back to slice through off a Mitchell Pearce pass early in the second half, but Oates' response six minutes later gave the Broncos a lifeline.
Mitchell and Oates spurned opportunities within 60 seconds of each other - the former ever so slightly fumbling and not re-gripping the ball before grounding it while the latter couldn't scoop up a botched Ferguson catch.
But the drama was only beginning. Hunt and Oates scored head-spinning tries, but Mitchell would have the last say. And didn't Ferguson thank him for it.
Sydney Roosters 24 (Aidan Guerra, Boyd Cordner, Luke Keary, Latrell Mitchell tries; Michael Gordon 4 goals) defeated Brisbane Broncos 22 (Corey Oates 2, James Roberts, Ben Hunt tries; Jordan Kahu 3 goals) at Allianz Stadium. Referees: Ben Cummins, Chris Sutton. Crowd: 21,212.