McLaren's Button claimed his second win of the season and the 14th of his Formula One career with the dominating performance, easily outdistancing defending Belgian GP champion Sebastian Vettel.
Button took advantage of a massive crash on the opening lap to quickly pull away.
The crash happened on the first turn of the 4.352-mile, 19-turn Spa-Francorchamps circuit, involving Ferrari driver and current points leader Fernando Alonso, McLaren's Lewis Hamilton and Romain Grosjean of Lotus.
While no injuries were reported in the mishap, Alonso looked shaken up as he slowly climbed out of his car.
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