Routinely down on his haunches in back play and needing treatment at halftime, Ponga bagged a double and set up two other tries with sensational offloads.

After the Sharks had worked their way back from 20-12 down late to lead 22-20, Ponga broke their hearts with a 77th-minute try to win the match.

Youngster Brodie Jones was brilliant as a makeshift centre as he scored one try, saved two and got a ball away for Ponga's match-winner.

Taking a Blake Green kick that went backwards, Jones threw an offload for Tyson Frizell who flung the ball back for Ponga to charge onto it and score.

It was a cruel end for the Sharks, who had shown plenty of resilience given the axing of popular coach John Morris just three days earlier.

After Morris told them on Thursday he would continue to support them this season from afar, he would've been proud.

They didn't make a second-half error until the final two minutes chasing the match, while Will Kennedy was again great at fullback.

Chad Townsend also kicked what looked likely to be a match-winning sideline conversion in the 69th minute after a flying Mawene Hiroti effort in the corner.

Connor Tracey also starred filling in on the left wing as he scored another late try to put the Sharks back in the hunt, while Briton Nikora also looked dangerous and claimed a four-pointer.

But still it wasn't enough to end their hard week on a high.

"They're gutted," Hannay said.

"It's been a challenging week and we put in enough effort to come away with some reward for this effort.

"One thing I know about this group is they are not happy with competing. They want to win and despite the week we had we wanted to win tonight.

"We did enough to win, and we undid it."

And while Hannay rued penalties in the lead up to both Newcastle's second-half tries, Ponga was clearly the difference.

He had the Knights' first when he ran around onto a Mitchell Barnett ball, before the fullback laid on an offload for the second-rower to score minutes later.

Barnett's try was a piece of work from Ponga, as he pushed through the line with power before getting the ball away late.

It still had nothing on his second-half effort to send Jones over.

Just as the Sharks looked as if they had the ascendancy after fighting back from to 14-12, Ponga got a perfect ball back to the centre while falling in a Matt Moylan tackle.

"He played really tough," coach Adam O'Brien said.

"He lives with Connor (Watson).

"The both of them suffered from a virus so both were pretty crook and couldn't eat.

"Kalyn just deteriorated as the night went on. To do what he did was amazing.

"To put himself in the frame (for the match-winner), and the one he set up was an exceptional piece of skill."

Australian Associated Press