By Richard Rae
Red Bull's Sebastian Vettel re-ignited his world championship hopes with an emphatic lights-to-flag victory in the Japanese Grand Prix.
The German finished a second clear of team-mate Mark Webber, with Ferrari's Fernando Alonso in third.
McLaren team-mates Jenson Button and Lewis Hamilton were fourth and fifth.
Webber now has a 14-point lead, with Alonso second, tied on points with Vettel in third. Hamilton and Button fall back to fourth and fifth.
Hamilton had looked certain to finish ahead of his team-mate, but his run of bad luck in recent races continued.
Having started the race with a new gearbox, and taken a five place penalty on the grid to do so, Hamilton was in fourth with 10 laps remaining, but lost a gear, enabling Button to catch and pass him.
To add to Hamilton's frustration, he had made one of the best starts in the race, jumping both Rubens Barrichello and Nico Rosberg to move from eighth into sixth.
Renault's Robert Kubica was also quick off the blocks, taking advantage of another slow start by Webber to move past the Australian into second.
But the race had barely begun before it was over for Vitaly Petrov, Alonso's team-mate Felipe Massa, Nico Hulkenberg and Tonio Liuzzi.
The Russian clipped Hulkenberg's slow-starting Williams, while Massa, trying too hard to make up for an appalling qualifying, lost control after putting a wheel on the grass trying to cut through on the inside and wiped out the unfortunate Liuzzi's Force India.
Championship leader Webber must have been anticipating a tough fight to re-pass Kubica, but the field was still running under the safety car when the the rear right wheel simply came off the Pole's Renault.
It was a full six laps before the safety car came in as marshals cleared the various cars from the circuit, and Vettel nailed the re-start.
Within three laps, both Red Bulls were more than a second clear of Alonso in third, and the interest seemed to lie in the competition for the minor places.
Hamilton, on softer tyres, was tracking Button on the harder 'prime' compound in fourth and fifth, while Michael Schumacher passed his old team-mate Barrichello for sixth.
Hamilton pitted at the end of lap 22, Vettel and Alonso two laps later, Webber three. Button, on his hard tyres, was left out in front, but had no chance of building the sort of gap needed to emerge from his own pit-stop higher than fifth.
So it proved when the world champion came in at the end of lap 38. Just ahead, Hamilton was catching Alonso, but having started the race with a new gearbox - and be penalised five places on the grid for so doing - Hamilton then reported he had lost third gear. Button caught and passed his team-mate quickly.
With four laps remaining, and the leading positions settled, Nico Rosberg suffered a failure on his Mercedes, crashing out on the 'S' curves. Kamui Kobayashi delighted his home crowd with a series of spectacular over-taking moves to take his Sauber into seventh, behind Michael Schumacher.