The victory was the 24-year-old German's seventh in 12 races so far this year, with seven rounds remaining worth a maximum 175 points.
Britain's Jenson Button finished third for McLaren after starting 13th.
"Thanks you boys, what a race," Vettel whooped over the team radio after his team's second one-two of the season and his first win since Valencia in June.
Image: Red Bull driver Sebastian Vettel of Germany raises the cup after winning the Belgian F1 Grand Prix at the Spa-Francorchamps circuit in Spa-Francorchamps, Belgium, Sunday, Aug. 28, 2011.
Text: Reuters
Images: AP