Li Na beat Olga Govortsova of Belarus 6-2, 6-2, while unseeded Venus Williams toppled No. 12 seed Kirsten Flipkens 6-1, 6-2 in the first round, reports Xinhua.
It only took the 31-year-old Li 64 minutes to finish the match.
The two players had met each other three times before Monday's match, and Li had never lost to Govortsova.
Li will next face the winner between Petra Cetkovska and Sofia Arvidsson.
Though Venus won the first set comfortably, she knew Flipkens was a dangerous opponent, as the Belgian once came back from a 0-6 first set to beat her 2-1 in the Toronto Rogers Cup.
Venus refused to let that happen again. The seven-time Grand Slam winner found her own way of winning the match.
Venus would next meet Chinese veteran Zheng Jie in the second round. Zheng beat Kiki Bertens from the Netherlands 6-1, 6-3, in a later match.
In her only meeting with Zheng nine years ago, Venus won.