Lewis Hamilton ended the first free practice session for the Abu Dhabi Grand Prix fastest of all following an entertaining battle with new World Champion Jenson Button for the quickest time.
The pair dueled 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 10.
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 organizers 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, 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