Nico Rosberg wins season-closing Abu Dhabi Grand Prix

Abu Dhabi: Nico Rosberg ended his 2015 season in triumph on Sunday when he completed a hat-trick of victories in the Abu Dhabi Grand Prix ahead of his Mercedes team-mate and world champion Lewis Hamilton.

The 30-year-old German, who has produced remarkable dominant form since seeing Hamilton secure his third drivers` title at last month`s United States Grand Prix, made a perfect start from his sixth successive pole position and, pit-stops apart, was in control all the way.

Rosberg was celebrating his sixth win of the year and the 14th of his career. It was his first success at the Yas Marina circuit where Hamilton beat him in 2014 to take his second title.

Hamilton won 10 races this year, but on Sunday was unable to rediscover the form that carried him to the championship despite pushing hard through the middle and latter stages of the race.

Finn Kimi Raikkonen finished third ahead of his Ferrari team-mate, four-time former champion Sebastian Vettel and Sergio Perez of Force India.

Daniel Ricciardo was sixth for Red Bull ahead of Nico Hulkenberg in the second Force India, Felipe Massa of Williams, Romain Grosjean who marked his last race for Lotus with a surge to ninth and Daniil Kvyat in the second Red Bull.

The race was preceded by an announcement from the stewards that cleared Ferrari and the American Haas team, which is set to join the grid next year, of any wrong-doing in their joint use of the Ferrari wind-tunnel to prepare cars.

But the sport`s ruling body, the International Motoring Federation (FIA), made clear that such a relationship - and any kind of collusion on aerodynamic testing -- will not be permitted in future.

This announcement clarified the issues and closed a possible loophole, leaving the paddock to focus on the final contest in perfect sunset conditions with a track temperature of 29 degrees Celsius and the two Mercedes together again on the front row.

When the lights went out, Rosberg made a perfect start while Hamilton struggled to stay with him and had to engage his best defensive driving to retain second place.

Behind the two silver arrows, the luckless Alonso suffered a puncture in a collision with Pastor Maldonado`s Lotus, for which he was regarded as the guilty party, and given a drive-through penalty, taken after his necessary pit-stop for repairs. Maldonado was eliminated.

After a frantic opening lap, Rosberg led by 1.4 seconds and extended that steadily before making his first stop after 11 laps. Hamilton led briefly before he followed him in, rejoining third.

This came briefly after Bottas had crashed into the rear of Button in the pit lane, the Williams man taking a five-seconds penalty for an unsafe release from his garage.

Hamilton regained second after Vettel, running on the `harder` tyres after starting 15th, ran wide and off at Turn 17, the champion making short work of his pass under braking at Turn Eight. Rosberg remained more than six seconds ahead.

For a period, the Briton cut into that lead, reducing it to one second before Rosberg was called in for his second stop after 32 laps. Hamilton led and chose to stay out on old tyres. He led by 18.2 seconds after 35 laps, but faced a second stop knowing he really needed an advantage of 22 seconds, if possible.

Ferrari`s erratic weekend continued with another bungle in the pits when Raikkonen`s right front wheel refused to budge easily during a tyre-change, the Finn losing time that dropped him to fourth behind Vettel.

Hamilton finally made his second stop after 42 laps, re-joining on the harder tyres 13 seconds behind Rosberg with 13 laps remaining. His determination was evident. With 10 laps to go, the gap was down to 10.3 and with six remaining it was 7.5.

The chase was on under the desert floodlights, but Rosberg had the cushion of a controllable lead as he sped towards his third successive season-ending win with the aid of pit-wall crew keen to see a team one-two finish.