Polii qualified to compete in the women's doubles event at the 2020 Tokyo Summer Olympics. She competed in her third straight Summer Olympics with debutant Apriyani Rahayu. In the final, they defeated the 2017 World Champions Chen Qingchen and Jia Yifan in two straight games, 21–19, and 21–15. Polii and Rahayu became the first unseeded pair to win the gold medal in women's doubles. This was Indonesia's first Olympic Games gold in women's doubles. At 33 years and 356 days, Polii is the oldest female badminton player to win a gold medal at the Olympics. With this win, Indonesia became just the second country after China to have won gold medals in all five disciplines of badminton at the Summer Olympics.