Wawrinka, summoning something from deep within, pushed the world No. 1 to his outer limits before losing 12-10 in the fifth set. The match lasted longer than five hours -- and, more than three years later, the confidence the 31-year-old Wawrinka gained is still with him.
"That's when I start to believe and realize myself that, 'Yeah, maybe I can beat top player in Grand Slam,'" Wawrinka said Friday. "It took me little time. I did it step by step by coming back into the top 10, by making first quarter, French, first semifinal."
Based on the head-to-head record, Sunday's US Open men's final between No. 1 Djokovic and No. 3 Wawrinka would seem to be a mismatch. Djokovic, the best player in tennis for five years now, maintains a 19-4 margin.
But in the crucible of the Grand Slams, Wawrinka has become a different, dominant player.
Two years ago at the Australian Open, he beat Djokovic 9-7 in the fifth set of their quarterfinal match, and then tagged No. 1-ranked Rafael Nadal in the final. It was Wawrinka's first major title, and it changed the trajectory of his career. The second came last year at Roland Garros, when he beat Djokovic in an astonishing four-set final.
"So," Djokovic said after beating Gael Monfils in a wacky four-set semifinal, "both of these Grand Slam trophies that he has, he won against me on the way. So I know right now, having two Grand Slam titles and Olympic medal and Davis Cup under his belt, he believes in himself more.
"He's a big-match player. He loves to play in the big stage against big players, because that's when he, I think, elevates his level of performance in his game."
According to Wawrinka, who beat Kei Nishikori in four sets in the semifinals, playing against Djokovic leaves him no choice.
"The secret is simple: I have to play my best tennis, my best game," Wawrinka said. "He's the No. 1 player, amazing fighter, amazing player, but I have enough confidence in myself that when I play my best level I can beat him.
"When you play Novak, the No. 1 player in the final of Grand Slam, it's the biggest challenge you can have."
And that challenge will be bigger Sunday because of the way this fortnight has unfolded.
Djokovic, who came in nursing right arm and left wrist injuries, received some extraordinary luck when three opponents were forced to quit: Jiri Vesely (withdrew from second-round match), Mikhail Youzhny (retired in the third round after six games) and Jo-Wilfried Tsonga (retired in the quarterfinals after two sets).
While Wawrinka has played a draining 23 sets and 237 games, Djokovic is at 13 sets, 118 games. He has a chance to tie or surpass the record for fewest sets and games in an Open era major that featured a 128-man draw and only best-of-five-set matches. John McEnroe won the 1979 US Open playing 16 sets and 150 games.
Wawrinka, who needed to save a match point against Dan Evans in the third round, has slowly rounded into form. In his past two matches, against Juan Martin del Potro and Nishikori, Wawrinka seemed to get stronger as time went on.
"I had no pain so far," Wawrinka said Friday. "I'm quite happy with my body where I am, and we will see now in two days. Hopefully I'm going to be fresh enough with Novak, who didn't have too much time on the court."
Aesthetically, this is a pleasing matchup. Djokovic said Wawrinka has the best one-handed backhand in the business and admires his variety. Wawrinka, who will be the more aggressive player on offense, acknowledges Djokovic as perhaps the game's best defender.
For Wawrinka, it all goes back to that match three years ago in Melbourne.
"I saw so many players not even thinking they can beat [the Big Four] when they step on the court," he said. "I always try to believe in something, that maybe one day I can beat them, and that's what happen in the past few years."
Wawrinka has won two of the past three meetings against Djokovic in Slams. On this occasion, the intertwined yin-yang of Wawrinka's belief will have to overcome a huge physical disadvantage.