Tamil Nadu's A Raegan netted seven goals (6th, 8th, 15th, 21st, 25th, 72nd and 90th) minutes of the game.
H Amiruddin and G Praveenkumar also scored at the 11th and 41st minutes of the game respectively for the winners.
Tamil Nadu led 7-0 at half time.
Earlier on January 16, Services thrashed Puducherry 8-0 in the inaugural match of Group B.
Karnataka will face Kerala in tomorrow's Group A match.