Referee Peter Gough labelled the tackle ”serious foul play”, which drew an immediate surprised response from skipper Daly Cherry-Evans.
Manly coach Des Hasler said the shot was ”careless” rather than ”foul play”.
“They were both genuinely trying to contest the ball,” Hasler said.
“Mitch is a brave player. It was a big part of the game. I thought Addin didn’t clip him too hard. The hand was open.
“I think the sin-binning was punishment enough. I think some of the booing was a bit unsavoury, but I’ll leave it that.”
Newcastle coach Nathan Brown confirmed that Pearce was fine in the sheds but his being forced from the field for HIA protocol was tough on them.
“It’s one of those ones where the player has some responsibility,” Brown said in reference to Fonua-Blake.
“Mitchell was in a very low situation, so it’s a tough one, isn’t it?
“Mitchell’s health is important to us. He’s good in the sheds now. The new rules of the game mean he had to leave the field, which hurt us bad.
“We lost our way there. Did he go out there to do it? I don’t think he did. With him getting sin-binned, and with Mitchell healthy, I’m happy with the result there.”
Fonua-Blake had only a few minutes earlier scored the easiest of tries through a yawning gap to all but seal the result.
The young Tongan prop was suspended in the opening round for taking out Benji Marshall after he had kicked but has been nothing short of brilliant for the northern beaches club.
If he is rubbed out, he will be sorely missed by the Sea Eagles as they chase a fourth straight win against St George Illawarra next Saturday night.
Curtis Sironen could also be missing after smacking Kalyn Ponga around the chops and forcing him from the field for a HIA.
Manly’s eight-point win meant Hasler has done what Trent Barrett was unable to do last year – win three on the trot.
Cherry-Evans celebrated his 200th game in style, and the skipper thought he had helped himself to a first-half try when he skipped around Kalyn Ponga only to have the ball knocked out from behind by Edrick Lee.
For the Knights, it was their fourth straight loss and talk about the future of Nathan Brown will become a hot topic.
To make matters worse, the Knights lost Aidan Guerra to a suspected broken leg late in the game.
Guerra burrowed his way over from dummy half in the second stanza to score a try, even though it appeared he had planted the ball down short. That point was not lost on Hasler.
Manly burst out of the blocks to lead 18-0 after 20 minutes with tries to Jorge Taufua, Reuben Garrick and Joel Thompson. Jake Trbojevic picked up the try assist for Thompson when he dropped the ball on to his right boot. They were not even put off by the early 7-2 penalty count in favour of the Knights.
Christian covers rugby league for The Sydney Morning Herald.