The World No. 1 dominated her Chinese compatriot in the women’s singles final to win 4-1 (11-9, 11-6, 11-6, 9-11, 11-6).
That victory means Meng now equals the record of Olympic champion Liu Shiwen, in winning three-straight titles.
All-around masterclass from Chen Meng in women's final
Chen asserted her dominance over her less-experienced opponent from the off, and was better in every facet of play.
The 25-year-old was especially clinical on return, winning 31 points on Wang's service.
Her forehand attacks were also clinical, and the match was closed out in 53 minutes.
Fan Zhendong returns to the top with two titles in a day
World Tour Grand Finals winner in 2017, Fan returned to the top tier of table tennis courtesy of a resounding 4-1 victory over his fellow Chinese, 11-6, 12-10, 11-6, 6-11, 11-8.
Five-time Grand Finals champion Ma fought bravely to the end, but had no answers to Fan's clinical strokes in the key moments, who now enjoys a 17-game winning streak!
Double delight for Fan
Fan's singles success followed him claiming the men's doubles title alongside Xu Xin
The duo dispatched Chinese Taipei's Liao Cheng-Ting & Lin Yun-Ju 3-1 in the final.
Liu Shiwen seals gold
There was another Chinese victory in the mixed doubles, where Xu and Shiwen claimed gold.
However, it was harder work for the No. 3 seeds, who rallied from 2-0 down against Jun Mizutani and Mima Ito, to secure victory 9-11, 6-11, 11-3, 11-8, 11-9.
Stellar year for Japanese teenagers
Elsewhere, the women's doubles final saw the only non-Chinese winners of proceedings, with Japanese teenagers Miyuu Kihara and Miyu Nagasaki beating Korea's Jihee Jeon and Haeun Yang.
Crowned World Junior champions earlier this year, Kihara and Nagasaki needed just three games to claim World Tour Grand Finals gold, running out 12-10, 11-6, 11-6 winners.
Ever wondered how China produces so many world-beating table tennis players?
Olympic Channel were given exclusive access at the Marvellous 12 competition, the national World Championships qualifier, and one of the world's competitive table tennis events.