Newcastle superstar Kalyn Ponga spent most of Friday on the toilet battling the effects of a stomach bug, but it was Cronulla who felt sick after he inspired the Knights to a gut-busting 26-22 victory at McDonald Jones Stadium that night.

Including the match-winner in the 77th minute after earning a penalty at the other end of the field, Ponga scored two tries, set up two for Mitch Barnett and Brodie Jones, and kicked three goals from five attempts for a personal haul of 14 points.

Knights coach Adam O'Brien said Ponga, who could be seen doubled over and vomiting on multiple occasions during the game, and housemate Connor Watson were both ill in the lead-up.

O'Brien said Watson did not train Thursday and slept into the afternoon on Friday, and though Watson showed signs of improvement, Ponga's condition deteriorated in the countdown to kick-off.

The coach explained Knights medical staff tried to give Ponga anti-nausea medication at half-time and he looked "a bit spent" after full-time, but there was never any consideration to replace him.

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"He played really tough," O'Brien told reporters after the game.

"Obviously he lives with Connor, and the both of them had suffered from like a virus, so they were both pretty crook, couldn't eat, and spent most of the time on the toilet the last 24 hours, so I was proud of both of them.

"To put himself in the frame, that one that he set up [for Jones] was an exceptional piece of skill, but he played tough all night [and] you could clearly see that he was carrying something as well.

"We'll get him on the mend and we're on again in six days [against Penrith]."

Cometh the hour, cometh Kalyn Ponga

O'Brien did not know what Ponga and Watson had eaten that caused their upset stomachs "but I'd steer clear of it", and hooker Jayden Brailey was unaware how sick Ponga was during the game.

"I knew he was crook – I didn't know he was spewing out the back – but he's a tough kid, he's been around the game for a while, and I thought he was unreal," Brailey told reporters.

"We just found a way to win tonight, he played tough, and a lot of us did but he played a big part in getting us the win."

Cronulla caretaker coach Josh Hannay believed his players contained Ponga for most of the contest but were punished for any defensive lapses.

"He's an outstanding talent, Kalyn, and the good ones have a habit of finding a way to hurt you," Hannay told reporters.

"I thought we did a pretty reasonable job on him for most of the night but whenever there was a little bit of broken play and we couldn't have that set line of defence against him, that's when he looked his most threatening tonight, and he was very good for them."

Ponga turns provider for Barnett

Ponga had an unlikely ally in makeshift centre Brodie Jones, who replaced winger Hymel Hunt in the seventh minute when Hunt limped off with a hamstring injury.

Jones, usually a middle or edge forward, played right centre and Enari Tuala pushed out to the wing.

Apart from making two try-saving plays and scoring his first NRL try, Jones set up Ponga's winning try when he recovered a speculative Blake Green cross-field bomb in the 77th minute.

"We lost a winger in the first five minutes so we put Brodie Jones in, who I thought was exceptional," O'Brien said.

"To do what he did tonight, he had a hand in nine plays, so that had me up and down too. I was excited."

Stomach pain can't stop Ponga's magic

O'Brien was pleased with his team's response to their unacceptable performance in a 42-16 loss to Gold Coast six days earlier but stressed they had to bring the same energy and effort levels to Penrith next Thursday when they challenge the unbeaten Panthers.

After successive losses to the Titans, Dragons and Wests Tigers, the Knights were desperate to turn their fortunes around against the Sharks in front of a loyal home crowd of 17,039, but now face the Panthers (away), Roosters (home) and Raiders (away) in the next three weeks.

"Certainly the wins are always important, but we needed to see a response, and our start to the game needed to have a whole lot more intent to it than what it had last week, and I felt that we've made some steps forward in that area," O'Brien said.

"But there's certainly a heap of things that we still need to be better at, and the good parts of it, that's the expectation. That's expected, and in six days' time it needs to be the same … it's got to happen next Thursday now."

O'Brien will seek clarification from NRL referees boss Jared Maxwell about the decision to award Sharks winger Mawene Hiroti a try in the 67th minute based on a video review which overturned referee Matt Cecchin's on-field decision of no try.

Bunker clears try for Hiroti as Sharks hit lead

Hiroti touched down as his feet were being dragged into touch by Knights debutant Brayden Musgrove and the try, when converted from touch by Chad Townsend, gave the Sharks a 22-20 lead.

O'Brien felt "confused" by the process after Tuala was awarded a try on field in Newcastle's loss to the Titans last Saturday only to have it overturned on video review.

"We've had some big plays that have hurt this footy team, and I need to get a bit more clarification around it," he said.

O'Brien expects to be without Hunt for at least the next few weeks and will consider several options, including keeping Jones in the centres, before settling on his backline to face the Panthers.