Vettel, driving for Red Bull-Renault, started in the second position Sunday but passed pole sitter Mark Webber on the first turn and never trailed. He covered the 55 laps of the 3.5-mile Korea International Circuit track in 1 hour, 36 minutes, 28.651 seconds for an average speed of 191.9 mph.
It was Vettel's fourth Grand Prix win of the season and third in a row. He won in Bahrain in the fourth race of the schedule but grabbed wins at Singapore, Japan and South Korea in the last four weeks. He has 25 wins in his career.
Webber, Vettel's Red Bull teammate, finished second Sunday, 8.2 seconds back of Vettel while Fernando Alonzo, driving for Ferrari was 13.9 seconds off the pace. Ferrari's Felipe Massa was fourth and Kimi Raikkonen, driving for Lotus, took fifth.
Vettel, the 2011 driving champion, has 215 points in the drivers' standings, six more than Alonso while Raikkonen (167) sits third with McLaren's Lewis Hamilton fourth with 153 points. Webber, with 152, is fifth.
There are four races left on the 2012 Formula 1 schedule. The next race is the Indian Grand Prix scheduled for Oct. 28. Vettel won the inaugural Indian Grand Prix last year.