2011 National champion Sourabh disposed off local shuttler Yi-Hsiang Yang 12-10 11-3 11-5 in the first match and then edged out Japan's Hashiru Shimono, seeded seventh, 11-6 8-11 12-10 11-3 in 41 minutes.
Sourabh, who had reached two finals at Belgium and Poland this year, will next take on Japan's Ryotaro Maruo.
National Champion Sameer Verma, who is the younger brother of Sourabh, had got a bye in the opening round.
But Sameer's campaign ended in the next round after losing 10-12 11-6 3-11 4-11 to Chia Hung LU of Chinese Taipei.
While Shreyansh suffered a 7-11 14-15 11-4 2-11 loss to Shih Kuei Chun of Chinese Taipei in the opening round, Rahul retired just after six minutes in the match against his Chinese Taipei rival Yang Chih Chieh with the scoreboard reading 2-6 in the first round.