Second seed Wei Feng conceded the match to Sourabh, seeded eighth in the tournament, as he picked up a back injury while practicing for the semi-final tie.
The world number 30 Sourabh had recently clinched three titles -- TATA Open, Austrian International Challenge and Iran Fajr International Challenge.
The only Indian left in the competition, Sourabh will now take on 15th seed Simon Santoso of Indonesia in the final at Stadium Pasir Gudang here tomorrow.
The 21-year-old is just one step away from winning his maiden Grand Prix Gold title. Sourabh had lost to Simon in his only encounter during the Indonesian Super Series in 2012.