Nadal ended Roger Federer's hopes of finishing a disappointing season on a high note, defeating the six-time champion, 7-5, 6-3, in the other semifinal.
Unbeaten in his round-robin matches this week, the second-seeded Djokovic extended his winning streak to 21 matches since losing in the U.S. Open final to Nadal. The two will play for the title Monday.
The world's two highest-ranked players are unbeaten this week and have faced each other five times this season, with Nadal winning three times.
After losing a set in each of his three previous matches, Djokovic raised his game Sunday by making only 14 unforced errors and breaking Wawrinka four times.
"The performance was definitely by far the best I've had in the tournament," said Djokovic, who is bidding for a third title at the elite event and has been the dominant player of the indoor season.
Nadal leads Djokovic, 22-16, but the Serbian won their latest match last month in Beijing after losing his top ranking to the Spaniard.
Nadal, who claimed his first win over Federer on an indoor hard court, extended his record over Federer to 22-10 and has now beaten the Swiss on every surface. Federer had won their four previous matches at the ATP Finals, dropping only one set.
"The most important thing for me is [that indoor] is the toughest surface for me to play," Nadal said. "The most difficult for me was to be able to win four matches against top eight players. It's a very good way to finish the year."
Victor Dubuisson held off some of golf's biggest names, including Tiger Woods, to win the inaugural Turkish Open by two shots for his first European Tour victory.
The Frenchman entered the day in Antalaya with a five-shot lead but with Woods, Justin Rose, Henrik Stenson and Ian Poulter among those chasing him. Dubuisson started the final round with nine straight pars but had three birdies on his last four holes for a three-under 69 that gave him a 24-under total of 264.
Jamie Donaldson of Wales shot a 63 — including a hole-in-one at the 16th — to climb up the leaderboard and finish second. Woods and Rose were another two strokes behind in a tie for third.
Kirk closed with a four-under-par 66 for his second career win, though he received plenty of help from Baird. They were tied for the lead playing the 18th hole at Sea Island when Baird drove into a fairway bunker, the ball below his feet. He topped a four-iron that went about 90 yards and into a hazard.
Kirk, who finished at 14-under 266, only had to make par for a one-shot win over Baird (67) and Tim Clark (62).
The victory sends Kirk to the Masters for the first time. He had been living at Sea Island for the last six years until moving back to Atlanta.
Sydney Leroux scored twice in the first half and the U.S. women's soccer team completed its sixth undefeated year with a 4-1 exhibition victory over Brazil at the Citrus Bowl in Orlando, Fla.
Leroux opened the scoring in the 15th minute, and Wambach scored on a penalty kick in the 17th. Rosana cut it to 2-1 in the 25th, and Leroux added her second in the 36th. Tymrak scored in the 76th.