Damani, who finished runner-up in Ahmedabad and Chennai, thus capped a memorable outing at home.
He started with winning the opening frame but was forced on back foot with Kothari snatching a 4-1 lead.
Damani however bounced back in style and kept winning frames to be in the driver's seat.
He settled the issue with three breaks in last three frames to clinch title.
The caravan will now move to Mumbai for Grand Finale where top 32 will vie for top honours.