McLaren set the pace in first practice for the day-to-night Abu Dhabi Formula One Grand Prix on Friday with Lewis Hamilton leading Jenson Button on top of the timesheets.
Red Bull's championship leader Sebastian Vettel was third quickest with Ferrari's Fernando Alonso, his closest rival 13 points behind in the standings with three races remaining, fourth as the team tried new aerodynamic updates.
Red Bull's Australian Mark Webber, who can be expected to 'ride shotgun' for Vettel in Sunday's race, was fifth.
Hamilton won in Abu Dhabi last year and he and Vettel are the only drivers to have qualified on the front row at Yas Marina in three editions of the race.
Such has been their dominance, that they are also the only two to have won the race while Red Bull and McLaren are the only teams to have lapped fastest in the 10 practice sessions held there to date.
Hamilton, who set a best time of one minute 43.285 seconds on Friday afternoon, has now been quickest in five of those 10 practice sessions.
Button was 0.333 slower while Vettel, winner of the last four races, was 0.765 off the 27-year-old Briton's pace.
Alonso's time of 1:44.366 was more than a second slower than the pacesetter.
"I don't know. Maybe ask Lewis," Vettel told reporters when asked on Thursday why he and Hamilton had such a great relationship with a harbour side track often compared to street circuits like Monaco or Valencia.
"Maybe he knows the answer. It's a difficult track, a long lap with a lot of corners. A lot of twisty sections. It's not that easy to get it right."
Red Bull can clinch the constructors' title this weekend but McLaren, who are still in contention for that championship, can throw a spanner in the works if they can carry over their practice form to the race.
The session saw a new face in Max Chilton, driving the Marussia for first practice only, but heavily tipped to become Britain's fourth driver on the grid next season.
The 21-year-old was 22nd fastest, a second behind Germany's Timo Glock in the other Marussia.
Finnish reserve Valtteri Bottas took Bruno Senna's place at Williams and had exactly the same time as Venezuelan Pastor Maldonado for much of the session until the race driver popped in a quicker lap.