Vettel, driving for Red Bull Racing-Renault, started at the pole of the 61-lap, 192.27-mile race after dark on Singapore's Marina Bay circuit and led throughout. He finished the race in 1 hour, 20 minutes, 46.172 seconds.
Vettel has nine firsts, four seconds and a fourth this year and is on the verge of wrapping up a second consecutive drivers' championship. He has 309 points with Button second at 185. Fernando Alonso, who drives for Ferrari and finished fourth at Singapore, is third with 184 points and Webber is in fourth at 182.
There are five races remaining on the 2011 Formula One schedule. The next race is Oct. 9 in Japan.
A finish of 10th or higher in Japan will give Vettel the drivers'' championship.