This makes him the youngest to win four such titles in a row, matching legends Michael Schumacher and Juan Manuel Fangio. The 26-year-old German, who had started the race from the front after leading Saturday's qualifying, has also won the 2011 and 2012 editions of the Indian GP.
On Sunday, Vettel was followed by Mercedes' Nico Rosberg and Lotus' Romain Grosjean in second and third."Unbelievable day. We did it! Yes! Yes!," Vettel was heard saying over the team radio.
Despite previous worries that spectator interest for F1 has been fading since the first edition in 2011, around 60,000 people came to Greater Noida's Buddh International circuit for the race, according to circuit owner Jaypee Sports International.
Traffic snarls on roads leading to and from the circuit reminded one of the huge rush seen in the last two years. "This year it was more fun because the rush was a bit lesser and there was better management. I have attended the race in the last two years as well, said Rohan Mahajan, an executive with a telecom firm.
A large section of the spectators were made up of ardent fans of the sport, including foreigners who had traveled from countries like Brazil and Australia to support their drivers.
Vettel, who had briefly dropped off the top 10 positions after an early pit stop on Sunday, later regained the lead from teammate Mark Webber.