The 17-year-old beat the eighth seeded Trupti Murgunde 21-17, 21-18 to advance to the third round where she will face Aruna M. of Pondicherry Saturday.
The youngster's superiority at the net helped her turn the tables.
"It is undoubtedly one of my biggest victories so far. This will give me a lot of confidence going ahead and I will try my best to as far as possible in this competition hereafter," Shriyanshi said.
In the day's other matches, tournament favourites P.V. Sindhu (women's singles) and defending champion Parupalli Kashyap (men's singles) sailed into the third round with ease.
Kashyap, who did not play the team event due a shoulder injury, hammered Tejan Fallary 21-4, 21-7 in only 14 minutes in the men's singles second round after a first round bye.
"It was an easy match. I am getting better with my fitness and was keen on playing. It is not always that you get to defend your national title so I am looking forward to put up a good show," said the top seed.
Earlier, World Championship bronze medallist Sindhu needed just 12 minutes to pack off Jaisy Bridgette 21-3, 21-15.
Also advancing to the third round in women's singles were third seed Arundhati Pantawane, fifth seed P.C. Thulasi and in men's singles third seed Ajay Jayaram, fourth seed Anand Pawar and fifth seed Kidambi Srikanth.
Important second round results:
Women's singles: 13-Aarti Sara Sunil bt Najma Khan 21-8, 21-7; 4-Tanvi Lad bt Moumita Talukdar 21-7, 21-4; 12-Mohita Sahdev bt Rupsa Ghosh 21-11, 21-6; 11-Ruthvika Shivani bt Ritu Vinayak 21-12, 21-11; 6-Saili Rane bt Tripti Lavania 21-15, 21-9; 14-Neha Pandit bt Anushka Kuvelkar 21-8, 21-6; 3-Arundhati Pantawane bt Nidhi Tiwari 21-11, 21-7; 5-PC Thulasi bt Sanskriti Chhabra 21-13, 21-7; 9-Mudra Dahinje bt Vaishnavi Bhale 21-13, 21-12; 2-PV Sindhu bt Jaisy Bridgette 21-3, 21-5.
Men's singles: 1-Parupalli Kashyap bt Tejan Fallary 21-4, 21-7; 11-Shubhankar Dey bt Manureet Singh 21-9, 21-12; 14-Abhimanyu Singh bt Sourabh Agarwal 21-12, 21-8; 4-Anand Pawar bt Gaurav Parmar 21-10, 21-13; 5-Kidambi Srikanth bt Aamir Sumara 21-6, 21-5; 3-Ajay Jayaram bt NN Vinayak 21-8, 21-13.
--IANS (Posted on 20-12-2013)