Britain's Lewis Hamilton drove a dramatic last lap on Saturday to snatch pole position for the Chinese Grand Prix, where he is aiming to become Formula One's youngest ever champion.

The 23-year-old McLaren Mercedes star delivered the fastest time in the dying seconds of a close-fought qualifying session to pip Ferrari's outgoing champion Kimi Raikkonen and title rival Felipe Massa.

It was Hamilton's seventh pole this season and the 13th of his career as he targets the drivers' championship, which he allowed to slip through his fingers despite an even more commanding lead at this stage of the season last year.

With just the Chinese and Brazilian legs to go, Hamilton needs only six points here to wrap up the trophy provided Robert Kubica, the only other title contender, does not win.

Two-time world champion Fernando Alonso, who is seeking a hat-trick of consecutive wins and has said he would support Massa's bid to overhaul Hamilton, will start fourth behind the Briton and the two Ferraris.

Hamilton's McLaren team-mate Heikki Kovalaien was only fifth ahead of Australian Mark Webber in a Red Bull. Webber has to drop 10 places because of an engine change on his car in the morning.

On a clear dry afternoon, the first part of qualifying was dominated by the McLaren men with Hamilton fastest ahead of Kovalainen with German tyro Sebastian Vettel third for Toro Rosso.

Red Bull's British veteran David Coulthard was livid that his final flying lap was spoilt by German Nick Heidfeld of BMW Sauber.

"This is one for the stewards, this is what they should pick up on," he said afterwards. "It was unsporting behaviour by Heidfeld. He had no intention of a faster lap. I have given him the benefit of the doubt, but this shows what sort of person he is."

Ferrari's Massa improved from fifth to second in the second session but he was again eclipsed by Hamilton, who had dominated Friday's practice and again ran in fastest after a switch to soft tyres.

Kubica saw his slim title hopes take a knock when he could not find the balance in his car and wound up missing the top-10 cut for the final session.

Hamilton produced a skittish opening run in Q3, putting him fourth, but roared back to form to deliver pole again.