Despite winning the 2015 Australian amateur championship, he had done very little in 12 months in the pro ranks.
One standalone T15 in his sole start on the PGA Tour at the 2016 OHL Mayakoba Classic in Mexico proved his enormous potential.
But he has one top-10 finish in professional golf, in a minor event. He missed the cut in his two previous Australian Open appearances and even missed the cut at the NSW Open last week, an $AUD400,000 event on the Australasian PGA Tour. His Official World Golf Ranking at the start of the week was No. 1494.
Yet there he was, with a stunned smile on his face holding the famous Stonehaven Cup that features the names of Gary Player, Jack Nicklaus, Arnold Palmer, Greg Norman, Peter Thomson, Tom Watson, Rory McIlroy and Jordan Spieth.
"It's a little bit numb at the moment," Davis said.
"I just didn't expect to be in this situation.
"I was just trying to get over that cut line. Before the week started that was the aim. I wanted to play the weekend in the Australian Open. It's the biggest tournament I've played in. I just wanted to get over the cut and play all four days and soak up the entire weekend."
The cut wasn't an issue after a stunning eight-under 63 on day one saw him grab sole possession of the lead by two shots. But even then, no one considered Davis a serious threat. Jason Day was lurking three back with a 66 that featured eight birdies.
Davis went backwards on Friday and Saturday with 72 and 74 while Day roared to the lead at 10 under.
They were supposed to keep heading in opposite directions on Sunday. But it was the kid who shot a stunning 64 in windy conditions, while the former world No. 1 struggled with a two over 73.
"I just tried not to get too far ahead of myself," Davis said.
"I think I did a little bit throughout the week. The second and third rounds didn't really go to plan and I think it's because I just got a little bit ahead of myself. I was in such a good position after the first round, it was a bit of hard work to stop myself from thinking too far down the track, and today I did the best job out of all the days just staying calm, staying patient, not thinking about the situation too much and just staying really relaxed and going through all the motions.
"To do all that and find out that it was enough to get over the line, it's crazy at the moment."
Four of the five played in the FedEx Cup playoffs this year. Jones, the only not to, won the last Australian Open held at this venue in 2015.
Jordan Spieth, who won his first Australian Open in 2014 with a final round 63 at the same venue, finished in eighth five shots adrift.
Meanwhile Davis has been slogging away on the Mackenzie Tour this year in Canada, sitting 76th on the money list with $7253 Canadian dollars to his name from 11 events.
But he had progressed to the Web.com Q school final stage prior to coming back to Australia.
"After the Mackenzie Tour finished I went through everything with my coach and we kind of figured out what went wrong, what I could improve," Davis said.
"I started getting on top of things a lot better and I started playing really good golf since then, through first stage and second stage of Tour School, which have been my only tournaments really between now and this. Obviously, I played the NSW Open last week and it wasn't that great.
"But I'd started to play some really good golf so I knew I was getting into pretty good shape. But I wasn't sure if it was good enough to win the Australian Open. I didn't realise it was going to be that good. But I'm glad it was."
Davis has the talent level to match the aforementioned names and this result proves as much. He's incredibly long, has a superb wedge game and putts beautifully.
He holed a wedge on 12 for an eagle two to tie the lead, and hit a low flighted wedge below the wind on 18 to a back right pin to set up the six-foot putt that would seal the title.
The putt was dead centre. He said he hadn't looked at a leaderboard all day and had no idea where he stood. But in 20 Opens at the Australian Golf Club no player has ever walked down 18 at 10-under par without a chance to win. He knew it was important and he finished the job.
The importance became apparent when he was told he had qualified for next year's Open Championship at Carnoustie, where Spieth is also defending champion, and would pocket an $AUD225000 cheque.
"It's my first major so I've got no idea what to expect," Davis said.
"I know it's going to be huge. I wasn't even thinking about that at all today. If I can follow in Spieth's footsteps, I'd be pretty happy.
"There's a whole lot of stuff coming that I'm not really aware of yet, but it's going to be good.
"I'm going to appreciate that. It's going to make life a lot easier, definitely. I don't know, I'm a bit speechless about all that kind of stuff. I wasn't thinking about that at all, all the way through the day, all the way through the week, I was trying to take my mind off that.
"I'm sure later on today I'm going to start looking around and seeing what this might get me but at the moment I'm just kind of a little bit numb to it all."