McLaren team mates Lewis Hamilton and Jenson Button laid down the gauntlet to their rivals during the first practice session of the Abu Dhabi Etihad Airways Formula 1 Grand Prix.
The British drivers clocked the top two times, with Hamilton leading fellow-Brit Button by 0.199 seconds.
World champion Sebastian Vettel and Fernando Alonso of Ferrari both crashed out during practice for the only twilight event on the F1 calendar.
Vettel eventually finished sixth fastest behind team-mate Mark Webber.
The Red Bull driver is the only winner at the Abu Dhabi Grand Prix which is being staged for the third time this year.
Yas Marina Circuit will again play host to the event, with UAE flag-carrier Etihad Airways again acting as headline sponsor.
The event provides the highlight of the sporting calendar in the emirate, with thousands of guests from around the world expected in Abu Dhabi over the weekend.
A host of new hotels are either welcoming guests or preparing to open in the next few weeks in the exciting destination.
Those hotels already open – including the award winning Emirates Palace – are doing their utmost to attract guests, with a shows from American chart sensation Britney Spears set to be among the many highlights.