Fonua-Blake was sent off after the siren following a dramatic final minute at Lottoland, as Newcastle claimed just their fourth ever win at Brookvale.

With the Knights leading by two points on the siren, Manly spread the ball right from within their own half as Tevita Funa broke down field.

The winger grubbered for himself from 20 metres out, but appeared to be taken to the ground by Tex Hoy and Bradman Best after kicking.

Referee Grant Atkins referred the play upstairs, bunker official Jared Maxwell ruled no penalty and fulltime was blown - drawing anger from a number of Manly players.

Jake Trbojevic and Fonua-Blake both crowded the referee before the latter was sent off for calling Atkins a "f-----g retard" while Cherry-Evans appeared to challenge the call.

Fonua-Blake was sent from the field and later apologised to Atkins with television audio clearly picking up the remark. He could still face a ban.

"Referees have a very tough job and we all need to respect their decisions even when we may not agree with them,'' Fonua-Blake said in a club statement.

"I should not have let my emotions get the better of me and I am very sorry for the comments I made.

"I'd also like to offer my sincere apology to anyone offended by the regrettable language that I used.

"I let myself and my club down. That is not who I am or want this club stands for."

A grade-two contrary conduct charge would attract a one-week ban if he takes an early guilty plea, while a grade-three charge would result in two matches.

However, it could be referred straight to the judiciary panel for a larger ban.

"Obviously he sent Addin off so we need to look at that," Manly coach Des Hasler said.

"I think from Addin's point of view it was emotion and frustration. You've got to take that. We have to wait and see what the charges and fall out of that is."

Hasler said he had not spoken to Fonua-Blake in detail about the incident before his press conference.

But he also insisted that Funa had been interfered with in the controversial play.

"He was certainly interfered with, otherwise they wouldn't have gone to the video referee," Hasler said.

"I have to check with Graham Annesley in regards to what the rule is in regards to the penalty and a shot at goal.

"I'm sure it's fine and in the rules."

The late drama overshadowed a gutsy win by the Knights that moved them into the top four.

Kalyn Ponga was one of three players to finish the match off the field for the Knights, taken for a HIA after falling awkwardly in a contest for the ball.

In a second half that contrasted with the first, Manly had 61 per cent of possession and had 22 tackles in the Knights' red zone.

But they could muster just one try, desperately missing backline stars Dylan Walker and Tom Trbojevic as they collected a second consecutive loss without them.

Manly's only second-half try came when Cherry-Evans helped Cade Cust burst through from close to the line from a Curtis Sironen offload in the 67th minute.

With Sione Mata'utia concussed and Edrick Lee suffering a broken arm that landed him in hospital, the Knights played the majority of the match with 15 men.

Andrew McCullough made 48 tackles while David Klemmer ran 188 metres and fellow prop Daniel Saifiti managed 164.

Australian Associated Press