Finally, Jason Day is ready for take off, and Jordan Spieth and Rory McIlroy have a new force to contend with in world golf's "post-Tiger" generation.

This was not on the same scale as Adam Scott's history-making Masters victory - that was a day for all Australian sporting fans and it gave golf in this country a shot of life.

This, simply, was Jason's Day.

Few golfers have had to endure more hardship, on and off the course, to win a major.

Now that he has, the 27-year-old becomes a legitimate contender, alongside the game's other under-30 superstars, new world No.1 Spieth and No.2 McIlroy.

Day, ranked No.5 before winning the PGA Championship, was already within striking distance.

But he could not truly stand beside the pair until he could show he could come through on the big stage.

Not only did he hang tough in some clutch moments in the final round, he did it going head-to-head with Spieth and - in doing so - must have sent a subliminal message to the game's "it" player that he is up for the fight in majors from now on.

Yes, he started with a two-shot lead on the classy American, but that doesn't always make it easier playing on Sunday in a major, and he out-played Spieth all round – out-driving and out-putting him on his way to a 67, one better than the US Masters and US Open champion.

Day's overall score of 20 under was the best to  par in a major. Ever.

It was an incredible display, made even more so by the fact Spieth was the one hunting him down. This was a pure match-up between two humble champions, and Spieth gained even more fans through his sportsmanship and magic scrambling game that one commentator observed: "made Harry Potter look inept".

Where Spieth and McIlroy stormed onto the major scene, it has been a grind for Day.

This was his 10th top 10 in a major and it finally sealed the deal.

As he walked to the 18th green, the legendary Sir Nick Faldo on commentary summed up what the victory meant in the game's bigger picture.

"We had the big three moons ago," the six-time major winner said, referring to the glory days of Jack Nicklaus, Arnold Palmer and Gary Player.

"And now I think we are approaching on having another big three in the game of golf."

That is a significant statement when you consider the place those three greats have in the game. To think Day could hold something similar, along with Spieth and McIlroy, is exciting.

That walk to the 18th must have been such a satisfying one for Day, and any number of thoughts could have been running through his head.

If you just took the last few years in isolation, this win would be sweet enough.

Remember, Day lost eight members of his family during the devastation wreaked by Typhoon Haiyan in the Philippines in November 2013.

And it was only a few months ago that he collapsed on the course during the US Open because of an ongoing illness. Throughout his career he has suffered injury and come through.

His father Alvin died of cancer when Day was 12.

Before he passed away, his father gave him his first golf club – a rusty three-iron that he found in a junkyard.

Shortly after his death, Day began drinking - he was a confessed "alcoholic" as a school boy - and getting into fist-fights regularly.

It was his mother, Dening, who - worried her son would be lost to the streets - sold the family's home when he was a teenager and borrowed money from relatives to send Day a few hours away to boarding school.

It was there he was given a book from his roommate about Tiger Woods and - amazed by the feats of the American at such a young age - Day began practising 30 hours a week to become what he is today.

So as he broke into tears before his last putt on the 18th green - an image that will live on forever - there was no doubt a special thought for the woman whom he owes so much, watching back in Queensland.

Had he not become a professional golfer, Day figured he "would've been working at a meat processing plant, like he [Alvin] did".

The hug he shared with caddie Col Swatton will also be a moment both will remember for their rest of their lives.

Swatton met Day at the boarding school and has been with him ever since – as his swing coach, caddie, mentor and father figure.

It's hard to imagine a closer player-caddie relationship.

And yet there was plenty to look forward to, as well, like a future that will include another baby soon, and so that embrace with his wife Ellie and young son Dash must have been the sweetest of all.

Scott's Masters win signalled a change in momentum for golf in Australia, for his return the following summer ignited a huge spike in galleries, free-to-air television exposure and media interest for the country's triple crown events.

Should Day return home this summer, a similar buzz could occur, but that was not was this was about.

This was simply a chance for the nation to be proud of one of its sportsmen, who achieved something by showing the good old-fashioned Aussie spirit. He never gave up.

It was a feel-good story, and it came at just the right time.

It was simply Jason's Day.