Earlier, former world No.1 Srikanth had to dig deep to outlast fellow Indian Tharun Mannepalli 15-21, 21-6, 21-19.
Malvika will next face eighth seed Denmark's Julie Dawall Jakobsen in the last four encounter.
I'm on right track, not really far away from my best: Sindhu
Top seed and 2018 winner Shi Yu Qi of China dispatched Indonesia's Chico Aura Dwi Wardoyo 21-13, 21-8 while compatriot Li Shi Feng, world number six, came from behind to beat Canadian Brian Yang 21-11, 18-21, 21-16.
Tanisha Crasto and Dhruv Kapila outclassed Adnan Maulana and Indah Cahya Sari Jamil in straight games in the first round match.
Saina showed signs of regaining her form on her way to a sensational win over Chinese world number 9 He Bing Jiao
Sindhu reminisces about life-changing past seven years, her maiden Olympic medal ahead of WC
Sindhu looked in complete control as she prevailed 21-15, 21-11 over world No. 36 Tan in a 29-minute match.
Reigning World champion P V Sindhu and B Sai Praneeth were handed easy group stage outings in the badminton draws unveiled on Thursday for the Tokyo Olympics, starting on July 23.