Manly lost superstar Tom Trbojevic to a hamstring injury before Daly Cherry-Evans kicked them to a gutsy 13-12 golden-point NRL victory over South Sydney.
The Sea Eagles had looked shot when Trbojevic limped from the field in the opening stages of Saturday afternoon's second half, but they held on in extra time when Cherry-Evans took his chance from 40m out in the 85th minute.
Manly were at stages down to just one man on their bench with 30 minutes to play, but fought back from 10-6 down at halftime to lead 12-10 late.
Adam Reynolds sent the game to extra time with a sideline penalty with nine minutes to play, but missed field-goal shots in the 80th and 84th minutes for the Rabbitohs.
However, Manly will be left to count the costs. Trbojevic injured the same hamstring he hurt in the pre-season, Corey Waddell copped a heavy concussion and Joel Thompson was placed on report for a trip.
Trbojevic had earlier been the Sea Eagles' best, putting them on the attack early in the game with a 40m break and scoring their first try when he cut through the Rabbitohs' right-side defence.
His latest injury came two months out from the State of Origin series opener in Brisbane, and after he reignited Manly's season in Christchurch last week against the Warriors.
Trbojevic had been untouched and performing a standard kick return when he pulled up sore and immediately limped up the tunnel.
His brother Jake then stepped up in his absence, forcing an error from Souths winger Campbell Graham for Manly's other try, when Manase Fainu scooped up the loose ball to score.
Martin Taupau also topped 200 metres, despite spending 15 minutes off the field in the second half with a HIA.
Both sides struggled to complete and made a combined 30 errors, in what was still a highly entertaining and at times frantic match.
Sam Burgess was again the Rabbitohs' best, scoring their first try after four back-to-back sets in the first half and creating plenty of opportunities.
Five-eighth Cody Walker also impressed as he darted across field to give Graham Souths' other try, however he at times looked troubled by his shoulder injury.