Novak Djokovic beat Rafael Nadal 6-3 6-4 in Beijing to win the China Open for the fourth time in five years.
The defeat was Nadal's first hardcourt loss of the season but he will nevertheless usurp Djokovic as the world No 1 when the new rankings are published on Monday.
Nadal has had the beating of Djokovic this season, coming out on top at the semi-finals at Roland Garros and last month's final at the US Open, as well as the Canada Masters.
But victory at Beijing's National Tennis Centre gave Djokovic a degree of revenge and improved his record in the Chinese capital to 19-0.
The second seed only showed rare glimpses of the form that has seen him win 10 titles this year, with his Serbian opponent racing to a 3-0 lead.
Djokovic then powered ahead, showing formidable power-hitting and prodigious length on his groundstrokes to take the first set in which he conceded only two points on serve.
The six-time major winner immediately broke in the opening game of the second set and then kept his nerve, holding serve until the conclusion of the match in one hour and 27 minutes.
"I have to say congratulations to Rafa because he deserves definitely to be number one of the world this year with the season that he has had," admitted Djokovic after the match.
"He is the best player so far in 2013, there is no question about it.
"I am just very happy to be able to continue to play well and hopefully I can maintain the rhythm."
The win made the 26-year-old Belgrade-born player the first four-time winner of the event following his successes in 2009, 2010 and 2012. He did not play in the 2011 renewal.
"I didn't play my best match this afternoon," said Nadal, who will return to the top of the rankings for the first time since July 2011.
"He played at a greater level with his serve. I was not able to have any chance when I was returning during the whole match.
"He was able to hit all the balls where he wanted to hit them, so when that is happening against a player like Novak you are dead."