Finn Butcher and Zack Mutton signed off in style from canoe slalom's under-23 and junior world championships in Italy overnight, collecting two of New Zealand's best-ever results at that level.

A day after Mutton's younger sister River won an extreme slalom bronze medal, the 18-year-old Rotorua paddler finished fifth in the highly-competitive junior (under-18) K1 final in his last year at that level.

Central Otago paddler Butcher went one better, meanwhile, narrowly missing bronze and becoming the first Kiwi individual to feature in an under-23 worlds final.

Having scraped through his semifinal in the 10th and final qualifying spot, Butcher paddled first in the final and posted his fourth-successive clean run at the championships, clocking 80.89secs.

'Starting off first in the final, you've got nothing to lose,” says the jubilant 23-year-old.

'I put down a pretty decent run and then just sat and waited. If you'd told me two weeks ago that I'd be able to lay down a clean run in the final of the under-23 world champs, I would've been bloody stoked and to be so close to a medal is cool as well. It was a cool to be up amongst the top guys and a pretty good way to sign off the under-23 category.”

Italy's Jakob Weger thrilled his home crowd on the Ivrea course by winning gold in 77.22secs, just 0.03secs in front of Bradley Forbes-Cryans (Great Britain), with Sweden's Eric Holmer third in 80.85secs. Butcher was just 0.04secs behind after his 80.89sec run, crediting his huge support team - which includes Olympic champion triathlete Hamish Carter - and a ton of hard work for his breakthrough performance.

'I'm just stoked that a lot of work came together for a moment that counted. I've been putting in a lot of work in New Zealand and not just in training - with my strength and conditioning coach, with my sports psychologist, with my nutritionist and with my coaches. I'd talked to Hamish about trusting the buildup and knowing I'd done all the work, it was all behind me and I'd done everything I could to prepare was pretty sweet.”

Mutton, who was eighth in the junior final last year, also qualified 10th after a nerve-wracking semifinal.

'I was pretty stoked just to be in the final because my semifinal was not good - I was pretty terrified actually,” says Mutton.

'I was shaking a fair bit on the start line and I didn't execute the run all that well but managed to slide through in 10th spot.”

He managed to turn it all around in the final, one of just four paddlers to dip under the 80sec barrier. Crucially, however, he had a slight touch on the seemingly innocuous Gate 5, picking up a 2sec penalty to drop his overall time to 81.84sec.

'After the semifinal, I got it under control, felt like a new person, and went sub-80 in the final, which I was really happy with. It turned into an 81 with my touch and it was a stupid touch, which sucks, but it was a really nice run and it was a good time. Overall, I'm pretty gutted but hopefully I'll be able to take some positives out of it soon.”

Czech Republic paddler Barta won gold, with his clean run of 79.40secs enough to hold out France's Anatole Delassus in 80.32, with another Czech paddler Tomas Zima (81.00) and France's Vincent Delahaye (81.26) just shading the young Kiwi.

Two other New Zealanders were in action on the final day of the championships, with Hannah Thomas finishing 19th in her junior C1 semifinal and 15-year-old George Snook knocked out in the quarterfinals of the junior extreme slalom. Swiss paddler Jan Rohrer, who spent last year in Rotorua on an exchange training with Mutton and Snook, ended up winning the extreme slalom final.

NZ finalists at world championship level:

U18: Zack Mutton (K1: 5th, 2018), Zack Mutton (K1: 8th, 2017), Daniel Munro/Luke Robinson (C2: 2nd, 2014), Callum Gilbert (K1: 8th, 2014), Mike Dawson (K1 9th, 2004), River Mutton (extreme: 3rd 2018).

U23: Finn Butcher (K1: 4th, 2018), Jane Nicholas/Haylee Dangen/Kelly Travers (C1 teams: 3rd 2014).

Open: Luuka Jones (K1: 4th, 2017), Donald Johnstone (K1: 5th, 1987), Mike Dawson (K1: 7th, 2017).