Hamilton on top in first practice

The Briton, 12 points behind the championship favourite going into the final race, lapped the Yas Marina circuit with a quickest time of one minute 42.869 seconds. He also had a spin that ended without consequence.

Rosberg, who need only finish in the top three under the floodlights on Sunday to be sure of his first championship after being beaten in the last two years by Hamilton, was 0.374 slower and second on the timesheets.

The Red Bulls of Dutch teenager Max Verstappen and Australian Daniel Ricciardo, who could play a major role in deciding the title outcome by getting between the Mercedes drivers, were close behind in third and fourth.

Triple world champion Hamilton, who has to finish in the top three to even have a chance of becoming Britain's first four-times champion, and Rosberg have each won nine races this season.

A collision between the two in the day-to-night race, as happened in Spain in May, would instantly hand the championship to Rosberg although both have played down the chances of that scenario happening.

"It's going to be a weekend like any other where I'm going to go for the race win and do what it takes to get that," Rosberg told reporters.

He added that his driving would be "within the limits of what's acceptable, of course."

Although the underdog, Hamilton has won the last three races and can count on strong support judging from the banners around the circuit.

"Lewis can Merc it happen," said one punning effort.

Ferrari's Sebastian Vettel, who won the first of his four championships with Red Bull against the odds in Abu Dhabi in 2010, was fifth fastest and Mexican Sergio Perez was sixth for Force India.

Brazilian Felipe Massa, in his 250th and last race, was ninth fastest for Williams while Britain's 2009 world champion Jenson Button was 20th for McLaren after being asked to return to the pits slowly during the session.

Button did only 10 laps, compared to Hamilton's 28, with mechanics still working on the car through the closing minutes.