Mark Webber produced a stunning lap at the end of qualifying to snatch pole position for the Korean Grand Prix from the grasp of Red Bull team-mate Sebastian Vettel.

Vettel had topped the first two sections of qualifying but Webber stepped up when it mattered with a lap of one minute 37.242 seconds to beat the German by less than a tenth of a second.

Lewis Hamilton was third in the leading McLaren while championship leader Fernando Alonso, holding just a four-point lead over Vettel, was fourth for Ferrari.

While Vettel will be frustrated at missing out to his team-mate, his chances of taking over the championship lead from Alonso look good with Red Bull proving to be the car to beat so far this weekend.

Hamilton, 42 points adrift of Alonso, recovered well after a disappointing Friday as he tries to keep his title aspirations alive, but he was very fortunate to avoid a collision with Michael Schumacher in the pitlane during Q3.

The German pulled out of his pit box into the path of the Briton, whose sharp reactions prevented a coming together.

Alonso was fourth and will hope Ferrari's encouraging race pace in practice will yield a strong race result, although he will have one set of super-soft tyres less than his rivals after being forced to use a set to get through Q1, which he ended 16th, just ahead of Hamilton.

Kimi Raikkonen was fifth in the first of the Lotus cars, with Felipe Massa sixth in the second Ferrari.

Romain Grosjean was seventh with Nico Hulkenberg a fine eighth for Force India ahead of the Mercedes of Nico Rosberg and Schumacher.

But it was a disappointing session for Button. The 2009 world champion was trying to improve during the final seconds of Q2 when the Toro Rosso of Daniel Ricciardo stopped in sector three, bringing out the yellow flags.

Button appeared to lift to allow for the caution flags, but others, including Rosberg, improved their times while the yellows were out, dumping the McLaren man out, although the stewards may yet decide to take a look at the incident.

Sergio Perez and Kamui Kobayashi were 12th and 13th for Sauber while Paul Di Resta was another frustrated by the yellows as he ended up 14th.

Pastor Maldonado was 15th ahead of the two Toro Rossos of Ricciardo and Jean-Eric Vergne.

Bruno Senna was again the man to join the Caterhams, Marussias and HRTs in the drop zone in Q1.

The Williams driver could potentially have put Hamilton out as he went for a lap on the super-softs, but a mistake at the penultimate corner ended his chances.