Centre Billy Smith and his Sydney Roosters now face anxious waits over the next couple of days, after dispensing archrivals South Sydney Rabbitohs 26-12 to enter the NRL top eight.
The result caps one of the competition's worst capitulations by the Rabbitohs, who led the table with eight wins after 11 rounds, but have managed just three wins and three byes over the final 16 to miss the playoffs altogether.
The Roosters are still alive, but just barely, needing a five-game winning streak at the end of the regular season to breathe life into their campaign. They have 32 competition points and sit seventh on the ladder, but their negative points differential leaves them vulnerable to Canberra Raiders and North Queensland Cowboys.
If the Cowboys topple defending champions Penrith Panthers on Saturday and the Raiders beat Cronulla Sharks on Sunday, Sydney will slip outside the post-season cut.
What part Smith might play in any further games remains to be seen, after his second-half try celebration went over the top, when he threw the ball at a security guard patrolling the fenceline, hitting him in the chest.
The guard was clearly not impressed, but restrained himself from anything but a death stare at Smith, who did not seem to apologise for his antics.
Otherwise, the much-hyped Roosters v Rabbitohs encounter - billed as another chapter in the infamous 'Book of Feuds' - largely failed to live up to its reputation. When the two teams met in last year's playoffs, five players were sent to the sin bin - two of them twice - in a spiteful affair.
With NZ Kiwis hardman Jared Waerea-Hargreaves suspended out of this fixture - and six more in the future - the bitter enemies took 70 minutes to fully express their hatred for each other, but by then, it was too late for Souths.
Roosters half Sam Walker regathered a rebound from his own kick and plunged over for the final try, then sparked a melee, by letting his opponents know their season was over.
South Sydney led briefly, when Cam Murray's try was converted by Lachlan Ilias midway through the first half, but Fetaliaga Pauga's try just before the break gave Roosters a 10-6 halftime advantage.
Captain James Tedesco stretched that margin soon after the restart, and tries to Smith and Walker sealed their victory.
Meanwhile, Manly Sea Eagles have consigned Wests Tigers to the wooden spoon with a 54-12 thumping that saw them run in 10 tries - two each to Tolutau Koula and Jason Saab
Wests, now coached by Kiwis legend Benji Marshall, managed just four wins through their season.
Sydney Roosters 26 (Allan, Pauga, Tedesco, Smith & Walker tries; Suaalii 2 converions & penalty) South Sydney Rabbitohs 12 (Murray & Chee Kam tries; Ilias 2 conversions)
Join Newshub at 5pm Saturday for live updates of the Warriors v Dolphins NRL clash
