Button grabs second consecutive pole

Sebastian Vettel and Rubens Barrichello were third and fourth, but as both have to take post-qualifying penalties, Timo Glock will make it two Toyotas in the top three.

Felipe Massa - the pole-sitter at Sepang for the past two years - will start only 16th after a misjudgement by Ferrari in Q1.

Trulli took provisional pole for Toyota early in Q3, but was then pushed back to third by Brawn GP's Button and Red Bull driver Vettel.

However Trulli stayed out for a second straight flying lap on the soft tyres and found a further 0.3s - moving back up to first by 0.004s over Button.

The Melbourne winner then raised the bar with a 1m35.181s run on his final flying lap, putting him half a second clear of the field.

Trulli also improved, but not by quite enough, leaving him second.

Third-placed Vettel will lose ten places due to his penalty for tangling with Robert Kubica in Melbourne, while fourth-fastest Barrichello is set to drop back five spots after changing his Brawn's gearbox in practice.

Glock beat Williams's Nico Rosberg to fifth, but the pair will actually share row two.

Mark Webber was seventh fastest in the second Red Bull, ahead of BMW's Robert Kubica. The Pole's team-mate Nick Heidfeld was squeezed out of the Q3 places when Alonso improved in the final seconds of Q2.

Kimi Raikkonen took ninth in another quiet session for Ferrari.

Having made it through to Q3 despite his poor health and Renault's unimpressive practice form, Alonso chose to only do one run and settled for 10th, suggesting he will start with heavy fuel.

The surprise of the session was Massa's shock early exit. Ferrari believed its first runs would be sufficient to easily get both drivers through so remained in the garage as most of its rivals headed out for final runs. The team could only look on helplessly as Massa was pushed back to 16th on the grid, while Raikkonen just made it through in 13th.

McLaren remained lodged in the midfield. Lewis Hamilton and Heikki Kovalainen took 13th and 14th places, just 0.019s apart, behind Williams's Kazuki Nakajima, who again failed to match Rosberg's qualifying pace.

The Force Indias were again pushed back outside the top 15 despite looking set to reach Q2 earlier in the first segment.

Giancarlo Fisichella and Adrian Sutil will start 18th and 19th, between Renault's Nelson Piquet and ahead of Toro Rosso's Sebastien Buemi, who went off the road on his final Q1 lap. This time his team-mate Sebastien Bourdais made it through to Q2, but could not better 15th.

Pos  Driver       Team                       Q1        Q2        Q3      
 1.  Button       Brawn-Mercedes        (B)  1:35.058  1:33.784  1:35.181
 2.  Trulli       Toyota                (B)  1:34.745  1:33.990  1:35.273
 3.  Vettel       Red Bull-Renault      (B)  1:34.935  1:34.276  1:35.518
 4.  Barrichello  Brawn-Mercedes        (B)  1:34.681  1:34.387  1:35.651
 5.  Glock        Toyota                (B)  1:34.907  1:34.258  1:35.690
 6.  Rosberg      Williams-Toyota       (B)  1:35.083  1:34.547  1:35.750
 7.  Webber       Red Bull-Renault      (B)  1:35.027  1:34.222  1:35.797
 8.  Kubica       BMW-Sauber            (B)  1:35.166  1:34.562  1:36.106
 9.  Raikkonen    Ferrari               (B)  1:35.476  1:34.456  1:36.170
10.  Alonso       Renault               (B)  1:35.260  1:34.706  1:37.659
11.  Heidfeld     BMW-Sauber            (B)  1:35.110  1:34.769
12.  Nakajima     Williams-Toyota       (B)  1:35.341  1:34.788
13.  Hamilton     McLaren-Mercedes      (B)  1:35.280  1:34.905
14.  Kovalainen   McLaren-Mercedes      (B)  1:35.023  1:34.924
15.  Bourdais     Toro Rosso-Ferrari    (B)  1:35.507  1:35.431
16.  Massa        Ferrari               (B)  1:35.642
17.  Piquet       Renault               (B)  1:35.708
18.  Fisichella   Force India-Mercedes  (B)  1:35.908
19.  Sutil        Force India-Mercedes  (B)  1:35.951
20.  Buemi        Toro Rosso-Ferrari    (B)  1:36.107