Sourabh beat Tien Minh 21-13 21-18 in a 43-minute clash on Friday to set up a semifinal clash against Japan's Minoru Koga, who beat Thailand's sixth seed Tanongsak Saensomboonsuk 21-13, 21-18 later in the day.
Verma, the reigning national champion, got a bye in the first round and beat Japan's Kodai Naraoka 22-20, 22-20 in the second. He became the lone Indian left in the tournament following the ouster of Siril Verma and Shubhankar Dey earlier on Thursday.
Sourabh raced to a 4-1 lead early on and kept his foot on the pedal to reach the interval leading 11-6. He continued in the same vein to record a straight forward win in the first game. The second game was a more level affair and it was Tien Minh who held a slended lead of 11-10 at the interval.
Sourabh then stormed to a 17-12 lead before the Vietnamese narrowed the lead down to 19-18. Sourabh kept his cool and did not allow his opponent to score any more points after that.