Going into the match 2-1 down from the first leg, the Koreans scored first through Kang Chae-rim after 31 mins in Suzhou.
Then, just before half-time, Choe Yu-ri scored a vital second away goal to put the visitors 3-2 up on aggregate.
With the game tied at 3-3, and both teams having scored two away goals on aggregate, the tie went into extra time.
And right at the end of the first period, former PSG player Wang scored again with a tidy left-foot finish to put China in front.
The visitors were unable to respond with the match ending 2-2 on the day, and China going through to their second consecutive Games having reached the quarter-finals at Rio 2016.