Lewis Hamilton won the Belgian Grand Prix with relative ease as Mercedes took a comfortable one-two victory and left the fighting to its rivals behind.
The victory gives Hamilton a 28-point lead in the drivers' standings, enough to retire from the next race and retain the top spot even if Rosberg wins. Hamilton never looked under serious pressure as he executed a perfect two-stop strategy and kept Rosberg, who dropped to fifth at the start, comfortably behind throughout.
Drama unfolded behind the top two on the penultimate lap when Sebastian Vettel, who was on a one-stop strategy, suffered a right-rear tyre blowout on the Kemmel Straight. It was the second blowout of the weekend after Rosberg suffered a tyre failure in Friday practice, but it is not yet clear if the two are in any way related. Vettel was attempting to hold off Romain Grosjean's Lotus at the time, who was on a more conventional two-stop strategy and tyres that were eight laps younger. The tyre failure allowed Grosjean and Lotus onto the podium for the first time since the US Grand Prix in 2013, but infuriated Vettel who slumped to 12th as a result.
At the start, Rosberg made a slow getaway from the front row and was immediately swamped at the first corner as Hamilton led on the run down to Eau Rouge. Sergio Perez made a brilliant start from fourth to second and drew alongside Hamilton as the pair closed on the chicane at Les Combes. Perez had a look around the outside of Hamilton, but backed out as soon as the Mercedes claimed the apex in order to retain second place. Vettel also made a strong start from eighth to move up to fifth by the second lap as Valtteri Bottas lost out and fell to sixth.
The first pit stops occurred on lap seven, shuffling Rosberg up to second, which he would retain for the rest of the race. Bottas' race went from bad to worse at his first pit stop after his team fitted one medium tyre and three softs. The mistake saw the Williams driver penalised with a drive-through penalty from which he never really recovered as he went on to finish ninth.
Rosberg pitted on lap 12 and Hamilton on lap 13, with Rosberg emerging 7.5s behind his team-mate. He started to close the gap, but Hamilton remained unflustered and was able to answer Rosberg's charge when the gap narrowed to four seconds. Grosjean was making moves already as he fashioned two passes at Les Combes, one on Daniel Ricciardo and one on Perez to take third. The gap between the Mercedes drivers remained stable until a virtual safety car (VSC) was deployed on lap 20 when Ricciardo's Red Bull lost power in the final chicane and stopped on the pit straight.
The VSC prompted a flurry of pit stops for Grosjean, Felipe Massa, Kimi Raikkonen, Max Verstappen and Bottas, while Vettel opted to stay out and moved up to third place. The VSC also saw Rosberg close to within 2.2s of Hamilton when the race restarted, but once again Hamilton was equal to the challenge and quickly stretched his lead again.
Ferrari opted to keep Vettel out on his ageing medium tyres until the end of the race in the hope he could retain third place from the drivers on fresher tyres behind. The plan was working until lap 42 when his right rear tyre unravelled and exploded on the Kemmel Straight. The failure instantly brought an end to Vettel's chances, while Grosjean came over the hill at Raidillon to be faced by flailing rubber and a quick promotion to third place.
Outside the top three, Daniil Kvyat resisted the urge to pit under the VSC and instead made his second pit stop six laps later and took on on soft tyres. The decision gave him an advantage against those who had stopped under the VSC and in the final few laps he carved his way through the order to finish fourth.
Perez did well to hold onto fifth ahead of Massa, Raikkonen and Verstappen, who had a shot at seventh on the final lap but ran deep at Les Combes trying to overtake the Ferrari ahead. Bottas and Marcus Ericsson took the final points on offer in ninth and tenth.