The winger, heading to Japanese rugby on a two-year deal come the end of the season, was arguably the difference in Friday's preliminary final against the Dolphins.
With the hosts on the attack at Suncorp Stadium, Nawaqanitawase held his ground and pinched an intercept that saved a certain Dolphins try, before scorching 90 metres to score one of his own.
In the second half he created something from nothing to assist a Rob Toia score, before steamrolling three defenders to notch his second of the match as the Roosters ran out 36-20 winners.
It was the latest in a long highlight reel before he steadies himself for a Rugby World Cup campaign in Australia next year.
"Just playing, having fun and doing my job where I have to," he said post-game after racking up more than 300 running metres.
"I get put into certain positions and have to find my way out of it ... and next week hopefully I come out of a lot more again.
"Before the game here or there, you think about scoring a try, or a pass, or a kick.
"Everyone dreams of doing stuff. I'll be dreaming again next week, to score a few tries in a grand final."
Nawaqanitawase was at last year's NRL decider, briefly, on promotional duties. It was just long enough to realise how badly he wanted to play in one.
"I've watched that many grand finals," he said.
"Last year I was at the grand final doing a Telstra promo and thought, 'You know what, I want to be here next year'. And here we are."
Roosters captain James Tedesco is among the onlookers wishing it was not the 26-year-old's last week at the club.
"The stuff he comes up with every week ... (I) haven't seen anything like it," he said.
"He always wants to do the tough stuff, the freakish stuff comes when he has that freedom.
"He just comes up with plays every week now and everyone's always amazed, but that's just how Mark plays."
Nawaqanitawase insists he will take a break before his Japanese journey begins, but his performances will surely have Wallabies coach Les Kiss attempting to get the flying winger on the end-of-year tour of Europe.
Coach Trent Robinson knows what the NRL will be missing next season.
"It's incredible to watch him play," he said.
"Such a carefree, instinctive player. There's lots that goes into (his attacking plays), then he defends well and runs hard.
"Usually it's compromised ... it's pretty rare to play the way he plays."
