Newcastle have railed against a late concussion test on Kalyn Ponga which sidelined the superstar for the final 10 minutes of their round one loss to the Warriors.

New Zealand's NRL outfit hung tough to secure a gritty 20-12 triumph at Sky Stadium on Friday night.

The Warriors won in Andrew Webster's first game as senior coach, sealing the points through Wayde Egan's 73rd minute try.

However, Newcastle's captain was an onlooker as the match was being decided, stranded after a bunker call for an HIA.

Ponga said he wasn't hurt and couldn't even identify the incident that led to referee Chris Sutton ordering him off the pitch.

"I couldn't believe it. Ten minutes to go. Game on the line. I'm literally fine," he said.

"It's usually an assessment, sometimes on the field where they check your balance. But that wasn't the case because it an independent doctor in a box somewhere."

Knights coach Adam O'Brien fumed at the decision.

"I have no idea why ... who, why or how?" he said.

"They bumped it to a category two, which meant that he came straight off the field.

"He's unaware of any incident. And he knows what they feel like."

The Knights battled their way through their season opener, with Tyson Frizell out early after a head clash and Phoenix Crossland sin-binned in the second half for a professional foul.

However, they started perfectly, stunning the hosts through Lachlan Fitzgibbon's try with 111 seconds gone after Charnze Nicoll-Klokstad made a mess of a high ball.

Nicoll-Klokstad barely put a foot wrong from that moment, scoring himself in the second half and, like Adam Pompey, producing a try-saving tackle in the last 10 minutes as Newcastle chased the game.

"Talk about resilience," Webster said of the "outstanding" Nicoll-Klokstad.

"He drops the ball in the first set and bounces back to be one of the best players in the field."

Rivalling Nicoll-Klokstad for best afield, Tohu Harris was enormous for the Warriors, producing 51 tackles.

After their early blunder, Edward Kosi and Bunty Afoa replied with first-half tries for the Warriors as they took a 10-6 lead into the break.

Former Knight Mitchell Barnett sparked the Warriors night, running though his old team-mates to start a move than ended with Kosi diving one-handed into the corner.

Afoa bustled his way past three to score under the posts.

The break did the trick for the Knights, who again started sharper and were rewarded.

After dishing to Fitzgibbon for the first try, Ponga's quick hands were pivotal once more as Hymel Hunt ran over, with Jackson Hastings' (2/2) conversion putting Newcastle ahead.

Nicoll-Klokstad benefitted from Brayden Wiliame's rampant run, and the Warriors were again on top.

Down to 12 men, Ponga unleashed magic to race past four and across the line, only for Nicoll-Klokstad to produce heroics and hold him up.

Shortly after, Ponga was withdrawn thanks to the officials' intervention, and Egan made the points safe after dummying from a play the ball.

The loss is Newcastle's first round one defeat in six seasons, and their 13th defeat of their past 15 trips to New Zealand.