Second seed Nehwal beat Ji Hyun 21-13 21-14 in 43 minutes to make amends for her quarterfinal exit from the All England Super Series in Birmingham last week.
The world number four Indian had beaten the unseeded Korean, ranked 19th, during the first round of Indonesia Open Super Series last year.
Nehwal, who had a subdued beginning to the year after recovering from a ligament injury, showed her mettle all through the tournament to swell her trophy cabinet.
Ji Hyun tried to keep pace with Nehwal till 7-7 but the Indian was indomitable as she broke off from their and surged ahead with gaint strides to pocket the first game comfortably.
In the second game, Nehwal was ruthless as she opened a four-point lead at 7-3, and held fort to canter to her first title of the season.
The 21-year-old Nehwal had won three Super Series titles last year -- Singapore, Indonesia and Hong Kong Open --besides winning the Commonwealth Games gold and India Grand Prix gold.
She also won the Indonesian Super Series in 2009 besides winning the Chinese Taipei Open Grand Prix Gold in 2008.