The 20-year-old was left out of the NRL side for round one but returned in round two with a masterclass to inspire a 38-0 win over St George Illawarra.
He will play No.7 away at Gold Coast on Saturday and has been earmarked by the Dolphins to lead them into the future.
Katoa was already on contract until the end of 2025 but chief executive Terry Reader said the Dolphins wrapped up the Tonga international to underline what a vital cog he is in the club's future.
"Isaiya is a wonderful player and a wonderful young man," Reader told AAP.
"For a young guy who played first grade out of school, nothing fazes him.
"He is a gentleman and a key part of the future of the Dolphins."
After leading the side to their win over the Dragons, Katoa said he was keen to keep his jersey after edging out Sean O'Sullivan for the position.
"Being a competitor, I'd be silly to say no," Katoa said.
"It is awesome we have the competition in the halves. We get along and, whoever gets picked, there is no bad blood between us.
"It was a massive step (against the Dragons) but I'm not going to dwell on it and give myself a clap.
"I am going back to the drawing board to focus on what works for me and what I can get better at.
"It is not about cheering myself on. One win does nothing for us."
Katoa played 20 NRL matches in his rookie season last year, mostly at No.6, but his game management skills are highly regarded by his teammates as a halfback.
Hamiso Tabuai-Fidow is full of praise for teammate Katoa. (Jono Searle/AAP PHOTOS)
"The boys love him. When he is in the team there is more control and we can play off him," fullback Hamiso Tabuai-Fidow said.
"His kicking game is spot-on as well."
Katoa has been working with sports performance psychologist Phil Jauncey as he looks to build his game.
"As a team, we talk with Phil Jauncey about not being passive and waiting for the game, or waiting for a teammate to do something," he said.
"It is about attacking it and not being afraid to get dirty, whether that is making the first contact or getting a touch early on.
"For me, that first five minutes sets a platform."
Coach Wayne Bennett has told his players to "perform or perish" this year and Katoa has embraced the message.
"He has been pretty ruthless with us in making sure that we are performing," Katoa said.
"If we are not he is not going to reward us, but he didn't put any pressure on me.
"He just wanted me to take control of the team, get my defence right and kick well."
6°C