Belgian GP: McLaren's Jenson Button takes pole position at Spa

Jenson Button took pole with a dominant performance in Belgian Grand Prix qualifying to head a topsy-turvy grid.

McLaren's Button headed Sauber's Kamui Kobaysahi and Williams' Pastor Maldonado, who was later demoted to sixth for impeding another driver.

Lotus's Kimi Raikkonen was fourth ahead Sauber's Sergio Perez, Ferrari's Fernando Alonso, Red Bull's Mark Webber and Lewis Hamilton's McLaren.

World champion Sebastian Vettel was down in 11th in his Red Bull.

But while the championship front-runners struggled, Button was in a league of his own throughout.

He produced three separate laps all within about a tenth of a second of each other and all well out of reach of his rivals.

The 32-year-old, whose last pole position was at Monaco in 2009 when he was driving for Brawn, ended up 0.298 seconds faster than Kobayashi.

"It's been quite a long time since I got my last pole position in Monaco," he said. "It's been emotional. Sundays have been good the last few years, but Saturdays have not always gone perfectly.

"It's so important to come back after the long break and have a good result. This is close to winning a grand prix for me."

Button admitted he had no idea why he was so fast.

"I really don't know," he said. "All day the car has been reasonably good, and on both tyres the car felt good.

"It's difficult to get a lap together this year with these tyres and even with the pole lap it still doesn't feel that great a lap. It's very difficult to do a perfect lap, which is something I struggle with with the way I drive."

The pace of the Williams and Sauber cars was a huge surprise - although they have showed strong pace during the season, they had seemed in recent races to be slipping back behind the established top teams.

Sauber's Kobayashi said: "We had good confidence in [our chances at] Spa. We expected a good weekend, but not to be second in qualifying. We expected a strong result, so we have a good chance in the race."

Raikkonen, who was a strong tip for victory after good recent form, ended up 0.632secs slower than Button.

Alonso, the world championship leader, was a further 0.1secs behind and narrowly ahead of title rivals Webber and Hamilton.

The surprises continued with Vettel, third in the championship behind Webber and ahead of Hamilton, struggling to 11th place.

Vettel did not look quick all day and he was unable to find the pace in his Red Bull to make it through into the top 10 shoot-out. He has a higher downforce set-up on his car like Hamilton, hoping it'll be better for tyre degradation in the race.

It is not the first time Vettel has struggled to make it into the final part of qualifying this year - the team admit that he has not been as comfortable with the car in qualifying trim than during his dominant title season in 2011.

Mercedes driver Nico Rosberg was the big early scalp, qualifying only 18th and being knocked out after the first session.

The German had had a troubled run-up to qualifying, missing three-quarters of the morning session - and therefore his only dry running of the weekend following Friday's rain - with a gearbox problem.

The team needed to replace his gearbox, which earned him a five-place grid penalty and a demotion to 23rd place on the grid.

The stewards found Maldonado, who finished third fastest, guilty of impeding Force India's Nico Hulkenberg in the first part of qualifying and handed him a three-place grid drop as a result.