Manly's smashing of Melbourne reassured them they can nail top four NRL teams, but they already had a believer in Storm fullback Billy Slater.
The Sea Eagles had lost twice each to pace-setting South Sydney and Sydney Roosters and drawn their previous clash with Melbourne before finally delivering a 28-8 hiding to the reigning premiers at Brookvale Oval on Saturday night.
Manly led 20-0 before halftime and would have won by an even bigger margin if captain and centre Jamie Lyon hadn't missed five of his seven kicks.
Coach Geoff Toovey downplayed the significance of knocking over another competition heavyweight after the lack of success against them earlier.
But his players were a little less guarded about the importance of the result, which guaranteed the Sea Eagles a top four spot and moved them above Melbourne into third.
"I guess that win was probably reassuring more than anything," halfback Daly Cherry-Evans said.
"We personally knew we had it (in us) but there was a lot of people out there doubting whether we had that ability to beat a top-four side so it was good to prove to everyone out there."
Slater didn't need Saturday's flogging to convince him Manly are legitimate premiership contenders.
"Even before tonight I knew that they were just as dangerous as the top two teams," Slater said.
"They showed that they are and I'm sure everyone will be watching out for them."
Winger David Williams and fullback Brett Stewart grabbed post-match headlines by contributing five tries between them.
However it was some excellent defence and the performance of Manly's pack - minus the injured Anthony Watmough and his replacement Jamie Buhrer, who suffered a game-ending rib injury in the second minute - that was just as influential.
"Externally they (the Manly forwards) probably don't get the credit they deserve," Cherry-Evans said.
"But internally here at Manly we appreciate the work they've done, not only tonight, but in the whole season.
"They are big powerful boys, they get quick play the balls and they are just going really well and it makes my job and (five-eighth) Kieran (Foran's) job so much easier."
Toovey said Stewart came off late in Saturday's game as a precaution because of a slight hamstring issue and would be monitored this week.
He said Watmough's knee was still quite sore and would be assessed later this week, but stressed he wouldn't take unnecessary any risks with him for the final round fixture against Penrith.
X-rays later cleared Buhrer of any bone break. However, he will miss at least one game with cartilage damage.
Fullback Stewart is expected to be available for the match against Penrith, although he could be rested ahead of the finals.
