Siddharth, who knocked out defending champion Mohit Mayur Jayaprakash on Thursday, came up with another brilliant effort by beating Karunuday 6-4 6-1.
Vishnu recorded a hard-fought victory over Ronit Bisht. Vishnu, who was runners-up to Yuki Bhambri in 2011, defeated sixth seed Ronit 6-3, 6(4)-7, 6-4 to sail into the final.
Defending champion Prerna Bhambri made it to her third successive women's singles final as she outplayed second seed Shweta Rana 6-3 6-2. She faces Karman Kaur Thandi in the title clash.
PC Vignesh and Kaza V Sharma notched up a 6-3, 6-2 win over Nitten Kirrtane and Saurav Sukul to win the men's doubles title.
In the men's s singles semifinal, Karunuday was leading 3-2 in the opening set when Siddharth switched gears and won three games in a row, breaking the top seed in the seventh. Siddharth served out the set and carried confidence into the second set.