McLaren duo on top in second practice

Going into the closing moments it looked like Hamilton and newly-crowned world champion Jenson Button (Brawn) would repeat their first and second places from the morning, before Kovalainen edged ahead of his team-mate with a late soft tyre run.

At the start of the session Hamilton had an early trip over the run-off area at the end of the long back straight before establishing himself in front following a quick exchange with Kovalainen.

Sebastien Buemi then repeated the strong practice form he had showed in both Japan and Brazil by producing an ever-faster series of laps that took him up to first and then increasingly further away from the pack. His advantage eventually reached nearly 0.8s, before others made gains and Hamilton reclaimed the top spot 36 minutes in.

That was where he stayed, as Button and Red Bull's Sebastian Vettel closed to within a few fractions of a second, until Kovalainen put softs on and improved to 1m41.307s.

Behind Button and Vettel, Toyota's rookie Kamui Kobayashi impressed greatly with fifth place, having been among the frontrunners for most of the evening.

Buemi fell to sixth, ahead of Mark Webber and Rubens Barrichello in the second Red Bull and Brawn respectively.

Adrian Sutil's brake problems continued, with the German pitting his Force India following a major lock-up at the end of the long straight. He later rejoined to take 11th.

Robert Kubica was consigned to the bottom of the timesheets when his BMW Sauber suffered an apparent engine failure on the exit of the first chicane after just 13 laps.

The session gave a preview of the lighting conditions the drivers will experience in Sunday's race, which also starts at 5pm local time. Practice began at dusk, but darkness soon descended on Yas Marina, leaving the circuit's floodlights to illuminate the majority of the session.

Pos  Driver       Team                       Time              Laps
 1.  Kovalainen   McLaren-Mercedes      (B)  1:41.307            35
 2.  Hamilton     McLaren-Mercedes      (B)  1:41.504  + 0.197   34
 3.  Button       Brawn-Mercedes        (B)  1:41.541  + 0.234   39
 4.  Vettel       Red Bull-Renault      (B)  1:41.591  + 0.284   37
 5.  Kobayashi    Toyota                (B)  1:41.636  + 0.329   34
 6.  Buemi        Toro Rosso-Ferrari    (B)  1:41.683  + 0.376   37
 7.  Webber       Red Bull-Renault      (B)  1:41.684  + 0.377   34
 8.  Barrichello  Brawn-Mercedes        (B)  1:41.831  + 0.524   38
 9.  Rosberg      Williams-Toyota       (B)  1:41.931  + 0.624   39
10.  Raikkonen    Ferrari               (B)  1:41.987  + 0.680   39
11.  Sutil        Force India-Mercedes  (B)  1:42.180  + 0.873   28
12.  Nakajima     Williams-Toyota       (B)  1:42.245  + 0.938   36
13.  Heidfeld     BMW-Sauber            (B)  1:42.278  + 0.971   36
14.  Trulli       Toyota                (B)  1:42.409  + 1.102   30
15.  Liuzzi       Force India-Mercedes  (B)  1:42.530  + 1.223   33
16.  Alonso       Renault               (B)  1:42.782  + 1.475   29
17.  Fisichella   Ferrari               (B)  1:42.932  + 1.625   37
18.  Grosjean     Renault               (B)  1:43.021  + 1.714   37
19.  Alguersuari  Toro Rosso-Ferrari    (B)  1:43.022  + 1.715   39
20.  Kubica       BMW-Sauber            (B)  1:43.708  + 2.401   13

All Timing Unofficial