After starting 2024 with hopes of solidifying a spot in the finals, the Raiders have won just one of their past six games and were unable to run down a gutsy Knights side, who withstood a late barrage at GIO Stadium on Sunday.
Knights fullback Kalyn Ponga got through his return game unscathed as he looks to win a recall for Queensland's State of Origin side, while centre Dane Gagai, who is also in contention to get picked for the Maroons for the July 17 decider, bagged two tries.
Would-be NSW centre Bradman Best did not get up to his rampaging best, but he did a solid job of containing Matt Timoko as the Knights claimed a second straight win.
The victory lifts Newcastle up to ninth spot, denied a place in the eight by virtue of North Queensland's inferior points differential.
Canberra looked set to put an end to their spluttering run of form when veteran prop Josh Papalii barged over after just six minutes.
Josh Papalii got the Raiders off to a flying start with an early try against the Knights. (Lukas Coch/AAP PHOTOS)
Newcastle had barely touched the ball, but with one of their first forays forward, Gagai breezed through some paper-thin Albert Hopoate defence to draw the Knights level.
And with hopes of an Origin recall beckoning, Ponga and Best sparked into life to help the Knights hit the front.
Ponga scampered down his favourite left edge, finding Best, who sent Greg Marzhew crashing over in the corner.
It meant the Knights had a 10-6 lead at halftime after Canberra five-eighth Ethan Strange had butchered a chance to draw Ponga and send Timoko in after one of the Raiders' few incisive breaks.
On their first set after halftime, Raiders lock Morgan Smithies threw a forward pass and Newcastle made him pay.
Sweeping from the right to the left, Gagai popped up to give the Knights an extra body, and he was able to finish a well-executed set play to add his second try.
Newcastle were looking to turn the screws, but as Ponga sought the killer pass approaching the Raiders' line, Elliott Whitehead intercepted.
The English Test veteran looked to his left and found Kaeo Weekes in support, with the fullback running 90m to touch down.
Trailing by four points with 25 minutes left, Canberra threw everything they had at Newcastle, but the Raiders were unable to come up with a winning play to crack the Knights' line.
Winger Xavier Savage went closest two minutes from time, only to knock on as he attempted to ground an Adam Cook kick to the in-goal.