The 28-year-old Swiss overcame top seed Nadal 6-3 6-2 3-6 6-3 at Rod Laver Arena on Sunday, having survived a crippling bout of nerves sparked by the ailing Spaniard's dogged fightback in the third set.
"It's quite crazy what's happening right now," the Swiss told reporters. "I never expect to win a grand slam.
"I never dreamt about that because for me, I was not good enough to beat those guys.
"I still think that I'm dreaming. It's a strange feeling. I saw so many finals. I always try to watch the final of grand slams because that's where the best players are playing.
"To beat Rafa today, even if he was injured, I think I played my best first set during the match; I was ready to play four hours or five to beat Novak (Djokovic) in the quarters, to beat (Tomas) Berdych in the semis.
"That shows me I'm doing the right thing since many years. That if you practise well, if you work hard, you will always have a chance to be in a great position to play your best tennis."
Having never taken a set in 12 previous encounters against the world number one, Wawrinka took the first at a canter in a brilliant display of clean hitting and broke Nadal to lead 2-0 in the second before the Spaniard's back problem flared.
Playing against a hobbled opponent, Wawrinka closed out the second set with ease but was left reeling as Nadal dug deep from his reservoir of grit to hold serve and break him.
The winners dried up to be replaced by nervous shanks, the momentum change completely throwing the Swiss.
"The problem is I didn't play well because I was waiting for him to miss, and that was a big mistake from myself," Wawrinka said.
"Because I was nervous, I was like, 'okay, miss, miss, make a mistake, because I'm not going to win the match because I'm nervous; I start to realise that I can win the grand slam."
Wawrinka galvanised himself between the third and fourth sets and though wobbling to hand back a break of serve, served out the match strongly, sealing it with an imperious forehand winner.
Wawrinka became only the third Swiss to win a grand slam title after Roger Federer and Martina Hingis.
Having long lived in the shadow of Federer, eighth seed Wawrinka will be world number three when the new rankings come out Monday, while his compatriot slides to eight.
The Melbourne Park triumph was arguably a year in the making.
Wawrinka was left heart-broken in Rod Laver Arena last year in the wake of a fourth round marathon when he pushed a stunned Djokovic to the wall.
Succumbing 12-10 in the fifth set, Wawrinka wept and said he could not have played any better.
The loss nonetheless became a watershed moment for the Swiss, who had suffered some terrible hidings against the rest of the 'Big Four'.
Failure became a badge of honour, and he had a quote from Irish playwright Samuel Beckett tattooed on his forearm, urging him to "fail better".
Teaming up with former world number two Swede Magnus Norman, Wawrinka underlined his steely determination by upsetting 'Big Four' scalp Andy Murray in the quarter-finals of the U.S. Open, before another heart-breaking five-set loss to Djokovic in the semi-finals.
By the time of his Melbourne Park re-match with world number two Djokovic, however, Wawrinka was a raging ball of fire.
By upsetting the triple defending champion in five sets, Wawrinka proved to himself that he had the serve, the backhand and the will to beat anyone, regardless of reputation or record.
Despite his new-found belief, the roller-coaster win in his first grand slam final was still too hard to process for Wawrinka.
"To win a slam, to be number three, both for me are a big surprise," he said.
"It's an amazing feeling. I saw Roger winning so many grand slams in the past, so now it's my turn to win one.
"So, yeah, I will need time to realise what I did in these two weeks.
"Because in the end, even if Rafa was injured, I think I deserved that grand slam because I won against Djokovic, I won against Rafa.
"I did an amazing two weeks, and I was playing my best tennis ever."
- Sports & Recreation