Lewis Hamilton blew away his rivals to claim his sixth straight pole position for Sunday's Belgian Grand Prix.

The world champion posted a best lap of 1.47.197 to leave Mercedes team-mate Nico Rosberg trailing in his wake by almost half-a-second.

It marked Hamilton's 10th pole from 11 races this season, and with it, an unassailable lead in the race for the pole position trophy - a title which Rosberg won last year.

Hamilton also leads Rosberg by 21 points at the midpoint to the season, with Belgium the first race after the August break.

Valtteri Bottas was third for Williams with Ferrari's Sebastian Vettel, winner last time out in Hungary, only ninth.

Meanwhile, Sebastian Vettel rued a "costly mistake" after he qualified only ninth.

The Ferrari driver, taking part in his 150th grand prix, dominated the final race before the summer break in Hungary to claim his second victory of the campaign.

But Vettel faces an uphill task to maintain the pressure on Hamilton and Rosberg.

"It was disappointing considering I had a good feel throughout qualifying and the worst lap, or worst part for us, was the last one," said Vettel, 42 points adrift of leader Hamilton in the championship.

"The lap was fine until the last corner where I went in too deep and had a very poor exit. I lost quite a lot of time.

"I had a brief look earlier and I lost two tenths - not enough to go P3 - but enough to go higher up than P9. It was a costly mistake on a day like that so I am not happy."