Sydney Roosters will have to defy 112 years of premiership history to claim an NRL three-peat after they were flogged 60-8 by South Sydney on Friday night.
In the fourth biggest win of their history, Wayne Bennett lauded Souths' attacking display as the best attacking display he'd ever been a part of as an NRL coach given the opposition.
Alex Johnston claimed the second five-try haul of his career, while Cody Walker scored two and set up four more in a dominant display.
It helped the Rabbitohs earn hosting rights for next week's elimination final against Newcastle, avoiding a trip to the Hunter after the Knights hours earlier dropped their bundle on the Gold Coast.
"There have probably been one or two (better attacking performances) in the career, but not against that quality," Bennett said.
"I'm very humble sitting here as a coach after that performance.
"We don't know what the future will bring, but nothing they do in the next month will surprise me."
The Roosters, meanwhile, are in tatters on the eve of the finals.
No team in the game's 112-year history has won the premiership that season after conceding 50 points in a game, while it was their worst defensive effort in a decade.
The flogging means they will have to face minor premiers Penrith to open the finals next week, provided Parramatta beat Wests Tigers on Saturday.
"It hurts a lot. Very embarrassing for us," coach Trent Robinson said.
"To go out and perform like that is really disappointing. You can't feel much worse."
But Friday night's loss could be just one of their worries.
Jake Friend left the field in the third minute after a head clash with Campbell Graham, with his left cheekbone already ballooning as he went up the tunnel.
He'll require scans, with any injury would come as a significant blow to the Roosters, given back-up hooker Sam Verrills is already out for the season with a knee injury.
Freddy Lussick has started at hooker previously this year when Friend has been out, while Lachlan Lam came off the bench at dummy-half against Souths.
But while the Roosters floundered with a 68 per cent completion rate and 34 missed tackles, the Rabbitohs' attacking dynamos starred.
Walker attacked on both sides of the field, regularly linking with Adam Reynolds in an ominous sign for their finals rivals.
Johnston became just the sixth Rabbitoh to reach 100 tries, going past Bob McCarthy and into their top-five try-scorers.
After the Roosters crossed first through Morris, Walker had his first impact when he dummied and broke down field in the 13th minute before crossing three plays later.
He was in the thick of things again moments later when a cut-out ball helped Alex Johnston break free, before a one-two with Bayley Sironen put the winger over.
The five-eighth was again responsible for Johnston's second, as they again caught the Roosters short on the right and a lofted cut-out ball put the winger over.
His second half was just as impressive, putting Corey Allan over under the posts shortly after the break before running onto a Graham grubber for his second try.
Meanwhile, Johnston moved to the top of the NRL try scorers list on 20, with his last three coming in the space of five minutes.
It included one presented on a dime from Allan, after the fullback passed the ball back to him over the tryline as Souths chalked up their biggest ever win over their arch-rivals.