Premiers Manly have now lost four games from four after their latest defeat, 26-12 away to Newcastle for whom fullback Kurt Gidley was outstanding.
The Sea Eagles aimed up in the opening quarter and got an early try through New Zealand international Steve Matai although his night ended prematurely when he was forced off with a shoulder injury.
The Knights struck back and added tries from Zeb Taia and Junior Sau giving them a narrow four-point lead at the break.
And they built on that lead after the restart with a score from James McManus before the brilliance of Gidley shone through for the home side who added tries through Aka Uate Gidley himself late on.
All Manly could muster was a last-minute consolation try to Shane Neumann.
Tries: Zeb Taia, Junior Sau, James McManus, Aku Uate, Kurt Gidley
Goals: Kurt Gidley 3
Tries: Steve Matai, Shane Neumann
Goals: Matt Orford 1, Shane Rodney 1