Tamil Nadu, who thrashed Andhra Pradesh 4-0 today, also qualified, along with Kerala, from the South Zone after the end of the qualifying round matches here.
The final round will be held in Siliguri.
Karnataka led 2-1 at half time but Kerala came back in the second session to snatch a win. Striker Usman turned the tide in Kerala's favour with a superb display as he not only scored the equaliser but was also instrumental in Shibin netting the winner.
The other match turned to be an one-sided affair with Tamil Nadu dictating terms on Andhra Pradesh. Winger Ameerudeen struck three goals while captain Sudhakar netted the other goal.