Down a set and a break on Friday, the third-seeded Wawrinka took control to oust Japanese Kei Nishikori 4-6, 7-5, 6-4, 6-2. He will seek his third major championship Sunday against the top-ranked Djokovic, who he defeated at Roland Garros in Paris in 2015.
Earlier in the day, defending champion Djokovic beat 10th seed Gael Monfils 6-3, 6-2, 3-6, 6-2, with the Frenchman adopting unusual tactics to try and counter the world number one.
Djokovic has a career 19-4 edge over Wawrinka. But the two players have been very evenly matched over their past five Grand Slam clashes, with Djokovic winning two contests at the Australian Open and one at the US Open, all in five sets, and Wawrinka defeating the Serbian in five sets in Australia and in four sets in the 2015 French Open final.
In the semi-final, two-time champion Djokovic raced to a 5-0 lead in the first set, but the 10th-seeded Monfils won three straight games and had a break point to get back on serve by giving the Serb a steady diet of slow slices and then counter-punching effectively when the Serbian tried to attack the net.
The strategy worked for a few games, although Djokovic righted the ship in time to hold serve and clinch the set and then looked like he was cruising to an easy victory when he grabbed a 6-3, 6-2, 2-0 lead.
The mercurial Frenchman, however, stormed back to win six of the next seven games by adopting a much more aggressive approach, striking 14 winners to Djokovic’s five to take the third set in 41 minutes.
But toward the end of that set Monfils started bending over at the waist and showing signs that he was either ill or struggling with his fitness.
That gave a clear edge in the fourth set to Djokovic, who wrapped up the victory in two hours and 32 minutes even though he called for the trainer to receive treatment on his shoulder during the contest.
With the win, the 29-year-old Djokovic, a two-time U.S. Open champion in 2011 and 2015, advanced to his seventh final at this hard court Grand Slam event and his sixth final in the past seven years. “I think we both physically struggled a little bit towards the end of the third and fourth set, long rallies and tense moments,” said Djokovic, who will try to win the 13th Grand Slam title of his career. “At the end of the day, I thought it was a good match. We played a four-set match. I think the crowd enjoyed it in the end.”
In the other semi-final, Wawrinka began poorly with 11 unforced errors — compared to just three for his opponent — in the first set of Friday’s second men’s singles semi-final and also went down an early service break in the second set.
But the two-time Grand Slam champion Wawrinka began taking control of the match at that juncture, stepping up his aggressiveness and effectiveness with his return of serve and backhand to win the second set and take a 4-1 lead in the third set.
The Japanese player made one final stand to tie the third set at 4-4, but the match slipped away from him when he dropped serve in the 10th game to fall behind two sets to one.
In the fourth set, Nishikori was a shadow of the player who upset second-seeded Scotsman Andy Murray in the quarter-final, hitting just one winner and committing 12 unforced errors.
Wawrinka, who eliminated big-hitting Argentine Juan Martin del Potro in the quarter-finals, finished the match with 38 winners and 37 unforced errors, compared to 27 and 47, respectively, for Nishikori. “I knew I could always come back,” Wawrinka said on court after the match. “My game plan is to be aggressive. I knew I could fight for three, four, five hours. I want to make them suffer and that’s what I did against (Juan Martin) Del Potro and today as well.”