Naomi Osaka beat former world No. 2 Agnieszka Radwanska 6-3, 6-2 in a singles match Friday to advance to the third round at the BNP Paribas Open.
Osaka, who upset two-time Indian Wells champion Maria Sharapova in the opening round, said she tried not to let her high spirits affect her second match.
"I tried not to get overconfident about that (win against Sharapova) and focused on playing my own game," said Osaka, currently ranked 44th in the world.
"I knew my opponent plays at a good pace, but I was able to stay mentally calm until the end," she said.
The 20-year-old Osaka capitalized on a mistake by the world No. 32 to break the Polish player's serve in the eighth game to go up 4-3 in the first set.
After winning 14 of 15 points when she landed her first serve in the opening set, Osaka's momentum took her through the second at the Indian Wells Tennis Garden, where she won five straight games to close out the match.
In the first round of the men's singles, qualifier Taro Daniel defeated Cameron Norrie of Britain 6-3, 1-6, 6-1 to advance.
Yoshihito Nishioka suffered a 7-5, 3-6, 7-5 loss to Marcos Baghdatis.