The historic World Squash Federation event, boasting a record entry of 26 nations, is the first ever to be staged in France, and the first to feature three all-glass show courts.
India, seeded 10th, had to dig deep to put it across Ireland, the No 7 seeds, 2-1, thus reversing the result of the same Pool G clash two years ago.
India's numero uno female player Dipika Pallikal paved the way with a four-game victory over experienced Irish champion Madeline Perry, but the squad number two Joshana Chinappa let slip a 2-1 lead to allow Aisling Blake, and Ireland, back into the tie.
But teenager Anaka Alankamony held her nerve to see off Laura Mylotte 12-10 11-3 11-7 to give India a sensational victory at La Parnasse Arena.
Pool G:
(10) India bt (7) Ireland 2-1
Dipika Pallikal bt Madeline Perry 11-9 11-8 7-11 11-8, Joshana Chinappa lost to Aisling Blake 9-11 11-7 11-6 8-11 9-11, Anaka Alankamony bt Laura Mylotte 12-10 11-3 11-7.