Seventh seed Sindhu edged out Ji Hyun, seeded sixth, 11-21 23-21 21-19 in a thrilling contest that lasted an hour and 24 minutes here. This was Sindhu's sixth win over Ji Hyun in nine encounter.
The two-time bronze medallist at World Championship, Sindhu will lock horns with local favourite Sun Yu, seeded eighth, in the summit clash tomorrow.
A jolted Sindhu then came up with a much improved performance in the second game as she locked herself in a battle of supremacy with Ji Hyun, moving neck and neck till 7-7. The Korean changed gears and entered the break with a 11-7 lead.
After the breather, Sindhu erased the deficit with four points but Ji Hyun again managed to march ahead and grab three match points at 20-17. Sindhu saved two match points with some gritty strokes, including an angled drop shot before drawing level. She reached a game point but wasted it before she sealed a long rally with a powerful smash to roar back into the match.
A superb forehand from Sindhu and an error from Ji Hyun helped the Indian grab two match points at 20-18. Sindhu eventually sealed it with a superb cross court smash.
Sindhu had reached her maiden Super Series final at the Denmark Open last year but the title eluded her as she lost in straight games to 2012 Olympic champion China's Li Xuerui.