The London Olympics bronze medallist staved off the challenge from Sindhu 21-14 21-17 in the women's singles summit clash, which lasted 40 minutes at the Babu Banarasi Das Indoor Stadium here.
The two-time champion was tested by her younger colleague but Saina kept her nerve to eventually break a 15-month title drought after appearing in her 22nd final of her international career.
"Sindhu played very well. It was a great match and the crowd enjoyed it. She is great player, and also in top-10. I am happy that I pulled it off.
"I was little nervous as I was playing in a final after a long time. But things went well for me," said Saina, who had last reached a final in the French Super Series in October, 2012.
Also Read
Sindhu earned her first point when Saina hit wide but the Commonwealth Games champion kept the pressure on her with some smashes to lead 8-2.
Sindhu slowly started retrieving the shuttles and engaged in rallies to narrow down the lead to 5-8 but she was erratic at finishing the points and lagged 5-11 at the break.
After the breather, Sindhu scored with the help of her accurate over the head smashes and smart net play to narrow it to 11-14. But she once again faltered with the length of her returns to allow Saina lead 19-13.