"I'm just doing my part," said Fusitu'a.
"When I get these opportunities to score or help out the team out wherever I can I do my best to execute every single time.
"That's what we train for and when I get those opportunities I don't want to miss any.
"It's something we've been building throughout the year and it can only get better from now.
"We know what the standard is for us and we're going to look to get better every week."
Coach Stephen Kearney was thrilled his big wingers were able to stamp their mark, despite Manly's tactic of finding touch to try and prevent Fusitu'a and Maumalo from getting the ball on kick-returns.
The Warriors first two tries to second-rowers Isaiah Papali'i and Tohu Harris both came after powerful runs from Maumalo and Kata put the Sea Eagles defence on their heels.
Another tough carry from Maumalo early in the second-half preceded Fusitu'a bursting through two tackles on his way to sending Johnson in for their third four-pointer in the No 7's 150th match.
"Both of those guys have done a tremendous job for us all season," said Kearney.
"I know the opposition came with a plan to try and stop them because they're pretty good momentum builders and for a good part of the season they've done that nearly every week for us and they've been great."
Fusitu'a and Kata are both expected to get the call up for Tonga's mid-season Pacific test against Samoa in Sydney on June 23, with Maumalo also likely to oppose them in a blue jersey.
"It's always great to pull on the Tonga jersey so I'm looking forward to getting into camp with the boys again and getting through that match too," said Fusitu'a.
The Warriors first have to get through next Friday's away assignment against the Cowboys in Townsville, where Kearney hopes they will continue their progression.
"There were areas of our game where we can be a lot better and as long as we have that attitude to wanting to improve our performance, the experience of the last half a dozen weeks has sharpened us for that, so it's about making sure that we make that happen."