final, they lost a tight match against the 2015 champion Mattek-Sands/Šafářová in three sets. Peng then competed in the Taiwan Open, where she reached her eighth WTA final without losing a set. In the final, she lost to the top seed and world No. 13 Elina Svitolina. She also reached the final in the doubles event with Hlaváčková and lost to Vesnina/Makarova with a match tie-break. She reached the fourth round in Indian Wells but fell in the first round in the Madrid Open against Carla Suárez Navarro. She won her second WTA singles title at the Jiangxi International Open in Nanchan, China defeating Nao Hibino in the final. 2018: TIU sanction In August 2018, Peng was banned for six months and fined $10,000 by the Tennis Integrity Unit (TIU) for coercion and offering possible financial reward so that her main partner would agree to withdraw from the ladies doubles, even after the sign-in deadline at the 2017 Wimbledon Championships. Her partner, Alison Van Uytvanck, refused and Peng withdrew from the tournament instead. Three months of her ban and $5,000 of the fine were suspended. Her former coach Bertrand Perret of France was also banned for three months. 2019–2022: Retirement Peng began her 2019 season at the Shenzhen Open. She retired during the third set of her first-round match against Kristýna Plíšková due to a thigh injury. In doubles, she and compatriot, Yang Zhaoxuan, won the title beating Duan Yingying/Renata Voráčová in the final. Peng was defeated in the first rounds at the Australian Open, Roland Garros, and Wimbledon, and in the second round at the US Open. At the Jiangxi International Open, Peng made it to the semifinals where she was defeated by Elena Rybakina. In doubles, she and Zhang Shuai reached the final but lost to compatriots Wang Xinyu/Zhu Lin. Peng lost in the second round at Guangzhou in singles but won the doubles title with Laura Siegemund, defeating Alexa Guarachi/Giuliana Olmos in the final. She was defeated in the first or second rounds in Wuhan, Beijing, and Tianjin but won against Zhu Lin in the final of the Suzhou Ladies Open. Peng started her 2020 season at the Shenzhen Open, where she lost in the second round to fifth seed and eventual champion Ekaterina Alexandrova. In Hobart, she and Zhang Shuai reached the doubles final but were defeated by Nadiia Kichenok/Sania Mirza. At the Australian Open, Thailand