Reigning world champion Sebastian Vettel snatched pole position for the Malaysian Grand Prix Saturday in the dying seconds of a dramatic qualifying session which was thrown into chaos by rain.

In his final run on a drying track, Vettel stormed across the line in a time of 1min 49.674sec, pipping Ferrari drivers Felipe Massa (1:50.587) and Fernando Alonso (1:50.727) with Mercedes pilot Lewis Hamilton fourth.

Red Bull's Mark Webber and Nico Rosberg of Mercedes will start Sunday's race from fifth and sixth. Kimi Raikkonen, last week's winner in Australia, timed seventh but was hit with a three-place grid penalty for impeding Rosberg.

McLaren's Jenson Button will occupy the fourth row alongside Force India's Adrian Sutil, with McLaren's new recruit Sergio Perez -- second for Sauber in last year's rain-interrupted race -- starting ninth and Raikkonen 10th.

"It turned into an interesting qualifying session," said Vettel. "It was quite tricky because some parts of the track were still wet and others were dry, but still all in all a very good session for us.

"We managed to save some tyres, which could be crucial tomorrow."

Malaysia's ever-present tropical showers had disrupted Friday practice, and clouds were again looming ominously as qualifying got under way.

With track temperatures at a sizzling 41 degrees Celsius (106 Fahrenheit), Sutil set the pace in Q1 with the Red Bulls of Vettel and Webber trailing in 15th and ninth respectively.

Rosberg was leading Q2 when the rain set in, effectively bringing the session to an early halt as the cars returned to the pits -- but not before Paul di Resta had twice lost control of his Force India.

With the cloudburst quickly easing, the cars switched to intermediate wet-dry tyres for the final qualifying shoot-out and officials disabled the DRS overtaking system in the slippery conditions.

Hamilton ran wide on the slick track but soon recovered to post the fastest time, before he was quickly usurped by Rosberg and then Vettel at the top of the standings after six minutes.

With two minutes left, Webber raced through to time quickest, a lead which lasted just seconds as Hamilton crossed behind him in a time of 1min 51.699sec, a lap which seemed to have secured his first pole position for Mercedes.

But with the chequered flag waving, Alonso bolted over the line with a new fastest time, followed immediately by Vettel who claimed his 38th pole position -- and boosted his bid to win a fourth straight world championship.

Vettel will hope to improve on last week's showing in Australia, when he also started in pole position but dropped back to finish third behind Raikkonen and Alonso.

"I think if you start in the front you always want to finish there as well. I think it will be a long race," said the German.

Teams will be bracing themselves for more rain on Sunday, after last year's long storm delay in a race which was eventually won by Alonso. In 2009, heavy rain forced the grand prix's cancellation after just 31 laps, with Button awarded victory.