The Warriors, minus half-back Shaun Johnson due to a groin injury, took the lead on Saturday with a try from Konrad Hurrell, but four unanswered scores – including a double from Peta Hiku – sealed victory for Manly before Simon Mannering's late consolation.
Geoff Toovey's men are now four points clear at the summit with six games to play following defeats for the Penrith Panthers and Canterbury Bulldogs.
Jacob Gagan scored twice for Cronulla Sharks as they handed the Panthers an 18-16 loss, which was compounded by the news that half-back and co-captain Peter Wallace will miss the rest of the season with a ruptured anterior cruciate ligament (ACL).
The Bulldogs, meanwhile, succumbed to a 20-12 home setback against the North Queensland Cowboys in a contest marred by a neck injury to Cowboys' prop James Tamou, although scans subsequently revealed he has avoided serious damage.
Those results allowed the South Sydney Rabbitohs to move into second place with a 34-18 success against lowly Canberra Raiders on Monday.
Alex Johnston, Bryson Goodwin and Adam Reynolds all registered doubles in the Rabbitohs' win, but their triumph was soured by another injury as captain John Sutton suffered medial ligament damage.
Wests Tigers' poor run continued with a 28-12 loss to fellow play-off contenders St George-Illawarra Dragons, which was followed by the announcement that negotiations over the contract of Tigers head coach Mick Potter have been put on hold until the end of the season.
Melbourne Storm handed their play-off hopes a significant boost by dispatching Brisbane Broncos 30-8, and are level on points with fifth-placed Sydney Roosters following the defending champions' 16-12 reverse at Newcastle Knights.
Elsewhere, Parramatta Eels beat Gold Coast Titans 24-18.