India's Anirban Lahiri held off compatriot SSP Chawrasia in a play-off at Delhi Golf Club to seal his second European Tour title in the space of three weeks.
Lahiri, who won the Malaysian Open a fortnight ago, began the final round seven shots off the lead but a closing 69 was enough to force extra holes as overnight leader Chawrasia stumbled to a 76.
The home pair returned to the par-five 18th for the play-off and with Chawrasia unable to make par after hooking his tee shot into the trees, Lahiri holed from 10 feet for birdie.
Lahiri had been four over par after 10 holes of his opening round but the win solidifies his place in the top 50 of the world rankings and effectively secures his Masters debut in April.
"It's incredible," Lahiri said. "Starting today I didn't really think I had a chance. It was really tough, one of the toughest days I have ever played at Delhi Golf Club and I am really happy to have accomplished this.
"It's been a childhood dream and to now keep the Indian Open trophy at home is very, very special."
Chances
The 27-year-old had crucially chipped in for par on the 17th in regulation as a number of players squandered chances to either win the title outright or join the play-off.
Sweden's Joakim Lagergren, Thailand's Prayad Marksaeng, Sri Lanka's Mithun Perera and Australian Marcus Fraser all finished on six under, with Perera the only player to birdie the par-five 18th.
Marksaeng three-putted the last from long range for par, while Fraser held the outright lead on nine under par after 12 holes only to double-bogey the 13th and drop another shot on the 16th.
Bangladesh's Siddikur Rahman began the day two off the lead on 10 under but slumped to a 76, like Chawrasia, to finish five under par.
Lahiri admitted he did not think seven under par would be enough to win, with course specialists Chawrasia and Rahman starting the day 12 and 10 under respectively.
"The way Siddikur and SSP especially have been playing they have been hard to catch all week and for me I was just trying to play well and give myself a chance on the back nine," he added. "There were about eight of us who could have pulled through and I feel really lucky and really happy.
"It's hard to come to terms with. Just a few months back I was in Spain in q-school and I was staring at not having my card with five holes to go (he birdied two of those to eventually finish 17th).
"It feels like I have skipped a couple of steps to where I've gotten to right now and it's a fantastic feeling. Hopefully I can keep playing well the rest of the year."
Chawrasia, who has now finished runner-up four times in his national open, said: "It's a great week. I played very well the first three rounds but the last round I played very bad. It was a little bit windy and that was basically the problem.
"Anirban is my good friend; it's the first time we played a play-off together and it was a good challenge but I just hit a bad shot with the tee shot.
"I've played very well this year and hopefully it will continue for the full year."