World number one Novak Djokovic beat Rafael Nadal 6-2 6-2 to win his sixth ATP China Open title.
Nadal, 29, in his sixth singles final of 2015, missed a chance to break Djokovic at 3-2 in the opening set to level the match in Beijing.
With a fightback not materialising and the Spaniard requiring treatment on his right foot at 1-1 in the second set, the 28-year-old Serb won comfortably.
Wimbledon runner-up Garbine Muguruza beat Timea Bacsinszky in the WTA final.
Djokovic, who won his eighth title of the year in 90 minutes, said Beijing had "definitely been the most successful tournament so far in my career".
"The fans give me reason to come back every year."
Nadal, who saved two championship points, said the top seed was "having one of the most memorable seasons in the history of our sport".
Of his recent own dip in form, Nadal added: "I have been improving in every single match. All matches are good practice for me. It's good energy for starting next season stronger."
In the women's singles final in Beijing, 22-year-old Muguruza of Spain won 7-5 6-4 in a hard-fought victory for her second WTA title, and will climb to fourth in the world rankings when they are released on Monday.
"It's amazing, and I can't wait to come back and defend my title next year," she said at the trophy presentation of her biggest title to date.
Wawrinka wins in Tokyo
At the Japan Open, Swiss top seed Stan Wawrinka beat Frenchman Benoit Paire 6-2 6-4 to win his fourth title of the year and the 11th of his career.
The 30-year-old French Open champion took 65 minutes to beat Paire, 26, who had a scan on his left ankle before the final and needed pain-killing injections to play.
Wawrinka, who is one of four players - along with Djokovic, Andy Murray and Roger Federer - to have qualified for next month's season-ending ATP Tour Finals in London, said: "It feels really great, it's been a special week. Four in one year is amazing."
Paire has since pulled out of the Shanghai Masters, which begin on Monday, because of his injury.