She received a wild card to the Guangzhou International and won her first WTA Tour main-draw match defeating Luksika Khumkum in the first round.

Duan also achieved her best results in ITF events near the end of 2012, reaching the semifinals of 100k+H Ningbo and the finals of 100k Suzhou, losing both matches to top-100 veteran Hsieh Su-wei.

Duan was due to make her main-draw Grand Slam singles debut at Wimbledon, but withdrew to compete in the National Games of China.

In July, she won her first WTA Tour title at the Jiangxi International Open, defeating Vania King in the final.

At the Australian Open, she had her best Grand Slam performance to date by defeating Rebecca Šramková and Varvara Lepchenko to reach the third round, where she lost to former world No.

Duan and Zheng Saisai reached the final of the French Open, losing to Tímea Babos and Kristina Mladenovic.

The following week, with Zheng unavailable, she partnered with Veronika Kudermetova for the first time to win the doubles title at the Wuhan Open, beating Mertens and Sabalenka in the final.