Ma defeated reigning champ Fan Zhendong to claim his sixth singles crown after Chen made it four consecutive titles with victory over Wang Manyu.
Reigning Olympic table tennis champion Ma Long and fellow Chinese star Chen Meng took the spoils at the season-ending 2020 ITTF Finals in Zhengzhou.
Chen claimed her fourth consecutive women's title, beating Wang Manyu in a repeat of last year's final.
Then Ma avenged his defeat in last week's Men's World Cup final to Fan Zhendong, winning in five games to claim his sixth ITTF Finals men's singles crown and his first since 2016.
"Perhaps it was not as closely contested as last week's final in Weihai, but each individual game was very tough. I had some lucky points and Fan gave his best, but I'm happy with the final victory." - Ma Long in his on-court interview
A week after Fan Zhendong defeated Ma Long in the Men's World Cup final, the pair met again in Zhengzhou.
Ma won the opening game on that occasion, and the reigning world and Olympic champion repeated that here 13-11.
But this time 'The Dragon' did not allow the top seed back into the match.
He took the second 11-7 and showed superb defence to save two game points from 8-10 in the third.
Ma won an incredible rally to go 11-10 up, somehow readjusting to a Fan forehand which hit the net and then the edge of the table, before closing it out 12-10.
Back came Fan to take the fourth game 11-9, but Ma was not to be denied.
The Rio 2016 singles and team gold medallist won the fifth 11-8 for his sixth ITTF Finals singles crown and his seventh in total having collected the doubles title back in 2006.
In the women's final, Chen Meng started strongly to go into a 10-5 lead with Wang Manyu looking slightly nervous.
Wang saved four game points before a superb exchange of backhands ended with Chen closing it out 11-9.
Despite dropping the first game, the 21-year-old looked far more confident in the second and soon went 6-2 in front.
Back came Chen to lead 9-7, but Wang fought hard and produced a superb crosscourt backhand return winner to save the game and make it 10-10.
The underdog then converted her second game point, taking it 13-11 to level the match.
The third game went to 9-9 in a match of the highest quality.
First Chen and then Wang twice squandered game points, before some big forehands saw the world number one edge it 14-12.
That proved to be pivotal as Chen then took charge, excelling in attack and defence to take the fourth game 11-8 before racing through the decider 11-5 to seal the five-game victory, 11-9, 11-13, 14-12, 11-8, 11-5.
Chen is the first women to win four consecutive ITTF Finals singles titles and, coming a fortnight after her first Women's World Cup triumph, she looks the one to beat with Tokyo 2020 eight months away.