Mehta's fairytale run in the tournament came to an abrupt end at the Meridien Hotel in New Delhi as his Chinese opponent collected an eighth ranking title - his second in a row after his Shanghai Masters success last month.
The last player to win back-to-back ranking events in one season was Ronnie O'Sullivan 10 years ago when he took home the European Open and then the Irish Masters.
Ding took the opening frame with a 52 clearance after Mehta failed to take several chances to get off the mark, and the home hope only potted two reds in the other four frames as Junhui consigned him to his chair for almost the duration of the final.
Breaks of 81, 107, 93 and 100 secured the trophy for Ding and continued his excellent run of form.
"I think I am playing the best snooker of my career," Ding said. "I have improved and I'm stronger. I still have a lot of things to learn.
"It feels great to be the champion at the first ever ranking tournament in India," added Ding, who beat the likes of John Higgins and Neil Robertson in reaching the final.
"Especially to play against Aditya in the final. I'm proud for myself and I'm enjoying this. I'll rest for the next few days then hope to do well in the next tournament."
Mehta, who landed his biggest pay day with a cheque for £25,000, said: "I have learned a lot from this tournament and there are a lot of positives. I have reached milestones ever year in my career and this is the greatest so far.
"My hard work is bearing fruit. I want to keep achieving my goals and make a career out of snooker.
"A few years ago I would never have predicted this. My heart has been in the right place and I have put the right amount of work in, and shown myself that nothing is impossible.
"I am very proud to have represented India in this tournament and for the fact that the event has been successful.