Manly must break a 109-year hoodoo to claim this year's NRL premiership after they were flogged 52-22 by St George Illawarra.
Never in the history of the NSWRL, ARL or NRL has a team won a title after conceding 50 points in a match - the closest being 2001 premiers Newcastle who dropped 49 in a late-season fixture.
Yesterday's flogging also marked the first time the Sea Eagles had conceded a half- century scoreline since August 2005 - some 307 matches ago.
"The players are embarrassed," coach Trent Barrett said.
"I'm embarrassed. I'm accountable to it just as much as the players."
The Sea Eagles were barely in the contest but for a 16-minute period after the break where they piled on four tries.
Their 30-0 halftime deficit was the biggest of any team this season, as they missed Apisai Koroisau (calf) and Brenton Lawrence (rested) in the middle, along with five-eighth Blake Green (rested).
The trio will return next week, but the loss left Manly's top-four hopes in serious doubts, after they dropped from third to sixth on the NRL ladder.
They must also travel to Melbourne next week to face the Storm, before hosting the second-placed Roosters the following week.
"It wasn't up to scratch," Barrett said.
"I don't want them to wipe it, I want them to be disappointed because you can't toss it up.
"To concede that many points isn't good enough and we've got to learn a lesson from it.
"The players are shattered and we all are, but it's just another lesson for us."
The result was particularly crucial for the Sea Eagles, given every other team positioned between first and ninth claimed victories in round 20.
Meanwhile the win for the Dragons kept them in eighth, two points behind Parramatta who held on to beat the Wests Tigers 17-16 on Sunday.
In a sea-sawing encounter, Corey Norman slotted over a late field goal to guide the Eels to victory and four points clear of the chasing pack for the eight.
Up top, Melbourne maintained first spot with a 20-14 win over Canberra, despite losing Cameron Smith to a minor pectoral injury and Billy Slater to a sickening Sia Soliola high shot.
Soliola was referred straight to the judiciary for the late hit.
The Sydney Roosters are second after they beat Newcastle 28-4, while Brisbane, Cronulla and North Queensland are all on 28 points and split only by for-and- against.
Penrith also emerged as the most likely to break into the finals with their 24-16 win over the Gold Coast, given the chasing pack of the Raiders Warriors and Canterbury both went down.