Hamilton heads first Abu Dhabi practice

The pair duelled for time towards the end of the session as both lapped faster than Red Bull's Sebastian Vettel.

Rubens Barrichello was fourth fastest as less than three tenths separated the top four. Nick Heidfeld was fifth quickest for the departing BMW team ahead of Sebastien Buemi. Adrian Sutil was seventh, having sat out most of the session with a gearbox problem.

Mark Webber, Jaime Alguersuari and Jarno Trulli completed the top ten.

Unsurprisingly the brand new 3.451-mile Yas Marina track was covered in dust at the start of the session, despite the best efforts of the circuit organisers over the last few days.

Thus only the Toro Rossos of Alguersuari and then Sebastien Buemi, and fellow rookies Kamui Kobayashi and Romain Grosjean did much of the running in the first 30 minutes.

Indeed it wasn't until the halfway point of the 90-minute session that the big guns began to fire as Vettel set a 1m45.372s ahead of team-mate Webber.

A few minutes later and Hamilton signalled his intent lowering the mark to 1m44.908s.

That's the way it stayed for a while as drivers began to find the limits of the circuit, laying that all-important rubber line down in the process.

Then it was Webber's turn to move to the top with a 1m44.805s, suggesting that Abu Dhabi could be a Red Bull kind of track.

But that's not counting for the Brawns, which up until the 70-minute mark had proved very quiet in the midfield.

Then Button, free of the shackles of world championship pressure, suddenly banged in a 1m44.524s to quickest.

This sparked a neat little cameo between Britain's two active world champions as Hamilton and Button traded fastest laps, the P1 spot moving backwards and forwards between McLaren and Brawn twice before eventually ending up in Hamilton's corner - with a 1m43.939s lap.

Several drivers found tricky spots on the new track. Button was among many to be caught out at the Turn 19 left-hander after the tunnel under the hotel, spinning harmlessly.

Kobayashi also had a spin into the complex of turns after the pit straight. No one though, remarkably ended the session with any car damage despite the closer proximity of the barriers at the new track.

Pos  Driver       Team                       Time               Laps
 1.  Hamilton     McLaren-Mercedes      (B)  1:43.939             18
 2.  Button       Brawn-Mercedes        (B)  1:44.035  +  0.096   20
 3.  Vettel       Red Bull-Renault      (B)  1:44.153  +  0.214   28
 4.  Barrichello  Brawn-Mercedes        (B)  1:44.207  +  0.268   23
 5.  Heidfeld     BMW-Sauber            (B)  1:44.667  +  0.728   23
 6.  Buemi        Toro Rosso-Ferrari    (B)  1:44.687  +  0.748   32
 7.  Sutil        Force India-Mercedes  (B)  1:44.688  +  0.749   14
 8.  Webber       Red Bull-Renault      (B)  1:44.805  +  0.866   25
09.  Alguersuari  Toro Rosso-Ferrari    (B)  1:44.955  +  1.016   33
10.  Trulli       Toyota                (B)  1:44.958  +  1.019   25
11.  Kubica       BMW-Sauber            (B)  1:44.988  +  1.049   22
12.  Kovalainen   McLaren-Mercedes      (B)  1:45.123  +  1.184   20
13.  Rosberg      Williams-Toyota       (B)  1:45.649  +  1.710   27
14.  Nakajima     Williams-Toyota       (B)  1:45.679  +  1.740   25
15.  Raikkonen    Ferrari               (B)  1:45.704  +  1.765   27
16.  Alonso       Renault               (B)  1:45.865  +  1.926   23
17.  Liuzzi       Force India-Mercedes  (B)  1:46.239  +  2.300   22
18.  Fisichella   Ferrari               (B)  1:46.267  +  2.328   26
19.  Kobayashi    Toyota                (B)  1:46.364  +  2.425   28
20.  Grosjean     Renault               (B)  1:46.411  +  2.472   27

All Timing Unofficial