The Ferrari driver did well to come second, 9.4 seconds behind the German in the 60-lap race.
Mark Webber came third in the other Red Bull as India's Olympic bronze medallist Gagan Narang waved the chequered flag at the Buddh International Circuit.
Vettel's finish was on expected lines after he was left untouched in the qualifying and the three practice sessions. It was his fourth straight victory and with three races to go, it would be hard to stop him from his third title in a row.
"It has been incredible last two years for us. The circuit has become special, I really like the flow of it though the first sector is quite challenging," said Vettel after collecting the winners' trophy.
Such was the dominance of Vettel that he had gained 28.1 seconds over Webber by his first pit stop.
The battle for the second and third was intense before Alonso got his nose ahead on lap 45. Webber faced issues with KERS and Alonso pressed the DRS button to get ahead of the Australian at turn four.
McLaren's Lewis Hamilton dropped a place from his grid position to come fourth, followed by teammate Jenson Button. Felipe Massa was sixth in the Ferrari while Kimi Raikkonen drove his Lotus home in seventh place.
Sahara Force India's Nico Hulkenberg finished eighth, having started from the 12th position on the grid, ahead of Lotus' Romain Grosjean and William's Bruno Senna, who picked up the final point.
Another Force India driver, Di Resta was 12th, improving four places on the grid. Narain Karthikeyan, the lone Indian on the grid, finished 21st for HRT.
Tyres worked well on the track as most teams perfectly executed one-stop strategy.
The race started with Alonso battling the McLarens on the long straight before getting past Hamilton for fourth position. The Spaniard then used the DRS on lap 5 to get ahead of Button.
The cars smoothly saw the first corner through, barring the collision at the back between Jean-Eric Verne and Michael Schumacher, causing a rear tyre puncture in the latter?s Mercedes. The veteran then struggled out the race and was classified 22nd.
For Force India, Hulkenberg quickly gained three places to be ninth and got past Perez on Lap 15 for eighth. He was running sixth at the time of first stop.
Karthikeyan struggled with cooling issues. His experienced teammate Pedro de la Rosa retired on lap 45 due to brake failure. Perez's race also ended prematurely, owing to a rear tyre puncture.