Because of rainfall at the Shanghai International Circuit, the race started behind the safety car and all drivers drove on wet-weather tires.
Vettel, who also grabbed the pole position during Saturday's qualifying, led the entire race with an average speed of 96.61 miles per hour.
It gave Red Bull Racing its first F1 win.
"It was the right decision to start behind the safety car, because there was quite a lot of standing water," Vettel said. "(The course) was OK at some points (but) it was very difficult throughout the whole race."
His Red Bull teammate, Mark Webber, finished second, Jenson Button third, with Rubens Barrichello fourth and Heikki Kovalainen completing the top five finishers.
Button leads the championship standings with 21 points to 15 for Barrichello, and 10 each for Vettel and Timo Glock.
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