Saina won 24-22 21-11 to keep her unbeaten record against third seed Buranaprasertsuk intact, extending it to 4-0 overall.
The Indian will be up against another Thai, second seed Ratchanok Inthanon, in the summit clash after the home player defeated China`s Lin Wang 21-13 21-19 in her semifinal match earlier today.
Going into the match, Saina had the psychological edge having beaten Buranaprasertsuk in their three previous encounters, the most recent being last year`s Denmark Open.
But Buranaprasertsuk seemed determined to turn the tables this time and she matched world number five Saina shot for shot in the first game.
The world number 17 Thai had in fact better statistics to show in terms of smash winners and net play in the opening game.
But not the one to give up too easily, Saina quelled the challenge by getting it right in terms of more consecutive points won which ultimately proved decisive and gave her the opening game.
Buranaprasertsuk seemed to have given it her all in the opening game itself and Saina took advantage of the fatigue factor by outwitting the local favourite with her deft net play to seal the match and remain on course for her second title of the season.
Saina had defended her title at the Swiss Open Grand Prix Gold in March in Basel, Switzerland early this year.