Fourth-seeded Mangaonkar, a quarterfinalist in the Welsh Open held last month, beat Malaysia's top junior and current world junior champion Eain Yow Ng 17-11, 11-4, 11-4, 11-5 in the semi-final, said a SRFI release.
Eain had earlier accounted for the top seed Peter Creed of Wales in the quarterfinal.
Mangaonkar will take on third-seed Greg Lobban of Scotland in the final tomorrow.
The Indian player's previous PSA tournament win came at the Sekisui Open in Switzerland last year.