Eighth seed Wawrinka claimed his maiden grand slam title in Melbourne on Sunday, producing a fine display to overcome Nadal - who struggled with a back complaint - 6-3 6-2 3-6 6-3.
Nadal, pursuing his second Australian Open title and 14th grand slam crown overall, looked set to retire in the second set after undergoing treatment on his back, which he said became "very stiff".
The Spaniard showed his trademark steely determination to battle back and take the third set after falling two sets down, but Wawrinka proved too strong in the final set and deservedly sealed his win in two hours and 21 minutes.
And Nadal was eager to focus on the "amazing" performance of the Swiss, rather than his own physical problems.
"That is not the moment to talk a lot about the back. It's Stan's day, not my day," the 27-year-old said.
"As I say before, I try my best and was not possible for me today.
"I'm obviously disappointed and very sad about what happened, but that's life, that's sport.
"For me (it) is a tough one tonight because I felt that I was ready to compete well, but in a few weeks that's going to pass.
"I'm going to keep playing, going to keep training hard, and I'm going to keep enjoying the world of tennis."
Wawrinka had lost all 12 of his previous meetings with Nadal while not winning a single set, but the world number one was effusive in his praise of the Swiss after Sunday's clash.
"He was playing amazing. It's very tough to stop him when he's playing that way. So just congratulate him," Nadal added.
"Because he's playing better and better and he's playing with amazing confidence, hitting every ball very, very hard, moving himself great.
"In a court like this one, the court goes quick, the bounces are a little bit lower and quicker than usual, it's very difficult when somebody's hitting every ball very hard and with that confidence to stop him."