Kathryn Norris and Hayden Hopewell have much shared golf history, but even for them, this was next level.

The West Australian youngsters are the respective Tasmanian Open champions of 2020 following another incredible coincidence in their young careers at Ulverstone today.

Amazingly, both were runners-up in this event last year, Norris to title favourite Becky Kay and Hopewell in a tense playoff with Aiden Didone having squandered a late lead.

And today, in exacting simultaneous revenge, they each stormed to their first state open crown by five-stroke margins.

"We always have done well in the same events through juniors at the same tournament ... we both won at the Nedbank Junior Masters (for example), and it's become a bit of a weird sort of joke between us," Mandurah member Norris said after she beat hometown hopeful Sarah Johnstone today.

"I sort of look for him to be near the top and then joke that I should go OK, and vice versa ... so it's nice to both get that win."

Norris, 19, was extremely impressive today, also seeing off fellow third-round leader Amelia Whinney, of Adelaide, by 10 strokes with a solid two-under-par 71 to finish at +2 overall.

"I didn't actually realise until afterward that I didn't have a bogey, so I was pretty happy with that ... just to be consistent under a bit of pressure was nice," said Norris, the only woman to break par on the final day.

Hopewell, 18, set up his victory with a dominant 36-hole performance during day two when he established a 10-stroke buffer.

And while the Royal Fremantle member didn't have his A-game in the final round, a birdie on the 11th was enough to steady a mid-round wobble and cruise home.

"It feels great because I had a four-shot lead here with nine to play last year, so that certainly fuelled me today," Hopewell said.

"I'm not going to lie, I wasn't rapt with three over (today) and I've probably limped over the line a little bit. "But I'm really happy with how I got there and it's all a matter of learning how to cope with all these situations in the future and it was important for me to steady and get the job done."

Hopewell finished at three under for the week, five clear of Sydney's James Conran who was occasionally brilliant today in carding five birdies on his way to a day's best round of two-under 70 and a +3 total.

South Australian Ben Tucker edged defending champion Aiden Didone by a shot to finish third, while sweet-swinging Greg Longmore was the best-placed Tasmanian one shot behind Didone in fifth at +10.

But Hopewell - who, like Minjee Lee, Hannah Green and Min Woo Lee, is coached by Ritchie Smith - showed ample signs of the promise many think he possesses.

"I'm hitting it a bit further than I was ... but really just knowing my game and understanding why things happen and having the experience to fix things on the spot and know how to react in certain situations," he said when asked where his improvement had come this summer.

"All I can do is put myself in these good situations ... and it's great to see the grind starting to pay off."

LEADERBOARDS