The 33-year-old Sydneysider is within reach of a career-best result at his home slam, after conjuring a mighty comeback to down qualifying lucky loser Dino Prismic 7-6 (7-4) 3-6 1-6 7-5 6-3 in the first round.
The epic triumph has catapulted world No.88 Duckworth from Court 6 onto Rod Laver Arena, where he faces a daunting task against second seed and four-time major winner Sinner.
"It will be tough," Duckworth said.
"He's obviously playing pretty well and he's pretty good in Australia, but if I come out and play aggressive, I can cause him some problems.
"I know it was a couple of years ago, but I beat him once before."
That was at the Canada Masters in 2021, more than two years before Sinner, who was then ranked 15th in the world, had won any of his major titles.
Sinner, 24, holds a 2-1 head to head advantage between the pair, who last met more than four years ago.
Buoyed by his previous victory over Sinner, Duckworth could also draw on the spirit of his late grandmother Beryl Penrose, who won the 1955 Australian Open women's singles and doubles titles.
Where would an upset of Sinner would rank among the family's tennis achievements?
"Probably not as good as hers - she won it - but it would be awesome and I'll give it my best," Duckworth said.
"It's what you train for, it's what you put in all the hours on the practice court and in the gym for.
"It's why you play tennis, to be in these situations, so it's really cool."
Local favourite Duckworth was roared on by a vocal crowd in his epic encounter with Croatia's Prizmic, and credited his fans with helping drag him over the line in the fourth and fifth sets.
He later doubled down on a suggestion he would lobby tournament director Craig Tiley to schedule the Sinner match on his preferred Court 6, rather than the much larger RLA.
"I'll definitely tell Craig that, but he'll tell me where I can stick that idea," Duckworth laughed.
"It'll be a great challenge. I'm looking forward to it, I'll prepare as well as I can and see how I go."
In stark contrast to Duckworth's five-set battle, Sinner was allowed to conserve energy with a first-up walkover against Hugo Gaston, who retired hurt from their match after just 68 minutes.
Sinner led 6-2 6-1 at that stage, having showed few signs of rust after a nine-week break between competitive matches.
"I'd probably say it is an advantage for him, but that's just the way it is," Duckworth said.
"I'm just going to try and get my body in as best shape as possible and give it a red hot crack."
Duckworth, who is contesting his 17th Open and 13th in the main draw, has reached the second round six times but has never reached the third.
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