Zhang, 24, won 18-16 11-5 11-6 10-12 13-11. This was Wang’s third successive defeat in an Olympic final.
A similar all-Chinese table tennis final was witnessed yesterday when Li Xiaoxia clinched gold, defeating team-mate Ding Ning in the women’s singles final.
Zhang dominated as China took their second table tennis gold at London 2012 after Li Xiaoxia’s win over team-mate Ding Ning in the women’s final.
Germany’s Dimitrij Ovtcharov beat Chih-Yuan Chuang of Chinese Taepei to win bronze.