A Dylan Walker try two minutes from full-time has helped the Sea Eagles down the Roosters 18-12 in an incredible contest at Allianz Stadium.
Manly had been the better side for the majority of the game, and after both teams had traded field goal misses, the Sea Eagles centre raced onto a perfectly-timed pass from Brian Kelly before sprinting 45 metres to break the deadlock.
Walker finished the game with 200 metres and two tries and was well supported by the back three as Manly extended their unbeaten run to three games, in turn ending the Tricolours' perfect start to the season.
Both teams bashed each other through the middle in an absorbing contest that looked destined to head to golden point before Walker stepped up to be the hero in the aptly named 'Superhero Round'.
Back-to-back indiscretions allowed Walker to knock over a gift penalty goal from in front to give the Sea Eagles an early 2-0 lead, but it was the Roosters who would cross for the first try of the evening through Shaun Kenny-Dowall courtesy of a brilliant cut-out pass from Luke Keary.
The Roosters then suffered a major setback when Dylan Napa limped from the field with an ankle injury, and things got worse for the home side from the very next set when Tom Trbojevic shot through a gap and then delivered a harbour bridge pass for Jorge Taufua to dive over in the corner.
Manly continued to apply pressure and were dominating the possession and territorial battle but were lucky to survive when Walker came up with a sloppy play the ball and compounded the error with some back chat, only for Michael Gordon to miss the relatively easy shot at goal.
Sea Eagles winger Akuila Uate looked to have broken the 6-all half-time deadlock just four minutes into the second stanza but had his effort ruled out after replays showed he had put a foot into touch.
With his side struggling for go-forward, Roosters firebrand Jared Waerea-Hargreaves threatened to turn the game on its head with an explosive carry out of his own end to win his side a penalty that woke the crowd from its slumber after they had been sent running for cover following a mid-game deluge.
However, the big man spilled the ball two sets later and then conceded a penalty of his own to put Manly straight back on the attack, although nothing came off it after Walker came up with an error close to the line.
Unperturbed by his mistake, Walker – who totally dominated his battle with Latrell Mitchell – made up for the error when he raced through to ground a Blake Green grubber to break the deadlock in the 66th minute.
Having been held quiet for the first 68 minutes, Mitchell burst into life with a trademark break down the left, but his good work was undone when Daniel Tupou spilled the pill with the line wide open.
Thankfully for the winger, his blushes were spared due to an offside call, and from the next set, Mitchell Pearce showed strength beyond his weight class to fight through four would-be defenders to bring his side level.
The Roosters halfback then had two bites at the cherry to knock over field goals from close range but had his first attempt charged down and then sent the second effort wide from directly in front.
After marching downfield from the seven tackle set, Manly earned a repeat set following a Mitchell error and then had the chance to win it from the usually-reliable right boot of Daly-Cherry-Evans, but he too sent his attempt to the right.
It mattered little as Walker delivered at the death to continue Manly's early-season resurgence.
Sea Eagles 18 (Dylan Walker 2, Jorge Taufua tries; Dylan Walker 3 goals) def. Roosters 12 (Shaun Kenny-Dowall, Mitchell Pearce tries; Michael Gordon 2 goals) at Allianz Stadium. Half-time: 6-6. Crowd: 12,376. Injuries: Dylan Napa (ankle)