For the world championships, nations can only send one athlete per race, leaving Fisher and Carrington to joust for the spot in the 500m race. Fisher took the spot and won the world title in 2021 when Carrington chose not to compete at the worlds, but they are now going head-to-head.
The national championship race doubled as the first of three races to decide who earns the ticket to the world championships, with the second to be held on Sunday morning and a third, if required, on Thursday.
"It's a bit cutthroat," Fisher said.
"It's pretty special having two of the best paddlers in the world in one country, and come the Olympics, we can both line up – you can have two spots.
"Until then I'm sure we'll keep each other on our toes. Both of us will keep getting better and at the end of the day that will be good for New Zealand as a whole."
To hear Fisher mention Olympic selection could be a welcome indication for the national programme, after the 27-year-old withdrew from consideration for the Tokyo team following a stand-off with Canoe Racing NZ over athlete welfare.
Fisher returned in May last year for the national championships, won the K1 500m title and went on to represent the country successfully at the world championships.
However, the reigning world champion wasn't getting too ahead of herself in terms of what was next, with another race win over Carrington still required to confirm her spot at the world championships.
"I just have to go out there and focus on my race, stick to my strengths and, I don't know, we will see tomorrow."
Regardless of whether she earns the 500m spot, Carrington is still likely to attend the world championships in the K1 200m, her favoured discipline.
Carrington easily progressed directly to Sunday morning's final in the 200m event at the national champs, clocking 43.92 seconds to win her heat by 2.72 seconds. Also directly qualifying as heat winners were Alicia Hoskin (43.11) and Teneale Hatton (43.49).