Ponnappa and Rankireddy got past Chinese Taipei's Lee Jhe-Huei and Wu Ti Jung 24-22 21-7 before edging out the Danish combine of Niclas Nohr and Sara Thygesen 21-16 19-21 22-20.
The Indians face another Danish duo, Mathias Christiansen and Christinna Pedersen, in the first round of the main draw tomorrow.
The leading Indian players, including Saina Nehwal and PV Sindhu, will also be in action tomorrow.
World number two Kidambi Srikanth pulled out of the tournament with a muscle strain.