Formula One: Nico Rosberg congratulates Lewis Hamilton

ABU DHABI (REUTERS/AFP) - Lewis Hamilton hailed Mercedes team mate Nico Rosberg as a "phenomenal competitor" on Sunday after the beaten German extended a congratulatory hand to his triumphant Formula One title rival.

Surrounded by his family and pop star girlfriend Nicole Scherzinger, the 29-year-old added the 2014 title to his 2008 win after cruising to victory in the season-ending Abu Dhabi Grand Prix.

"Perhaps things naturally will ease up a little now," said the Briton, a double world champion after Rosberg's bid to thwart him was hampered by engine troubles that left him out of the points. "He was graceful enough to come up to me and see me after, which I really appreciated. It was really big of him to be able to do that."

The two have been pushing each other hard all season in a campaign reminiscent of the great battles of yesteryear between Brazilian Ayrton Senna and French team mate Alain Prost at McLaren.

Boyhood friends since their karting days, the two Mercedes drivers tested their relationship to the breaking point with the pair barely on speaking terms as it became apparent that one of them would be champion.

In Monaco, Hamilton had suggested Rosberg had deliberately denied him a tilt at pole position with an error that brought out warning flags, while in Belgium in August he accused the German of crashing into him on purpose.

The latter brought everything to a head, with the team's non-executive chairman Niki Lauda admitting he had wondered whether the partnership could work, but the icy relations have thawed again.

"It's been so intense between us all year long," said Hamilton. "There's been good moments and bad moments.

"Without a doubt we've had a friendship or a relationship that we built a long, long, long time ago so that will always be there. "He was a very, very fierce competitor this year, he did an exceptional job. He's going to be quick for a long time...it could have been either one of us today."

Lauda, who beat Prost to the title by just half a point in 1984 when they were at McLaren, said the post-race handshake between Hamilton and Rosberg had made his day.

"I really got emotional when I saw on the podium that Nico went up and congratulated him," said the Austrian, himself a former triple champion. "Nico went up as a sportsman, normal and without negative emotions and congratulated him. This is the way life is and therefore I am very happy for both of them because it needs Lewis also to accept Nico's (hand)."

Hamilton described his winning of a second Formula One world title as the greatest day of his life.

"You know, I've been lost for words, but I really want to thank everyone, starting with the fans," said Hamilton, as he stood on the victors' podium after finishing first in the 'double jeopardy and double points' showdown.

"It's made such a difference to me, the amazing support - and to my family I love you guys. And to my team thank you. It feels even more than the first time."

"This is the greatest day of my life and that's due to people around me. 2008 was special, but the feeling I have now is above and beyond. It's the greatest feeling I've ever had."

Hamilton became the first British multiple champion for 46 years when he won Sunday's 55-lap race billed as the 'duel in the desert'.

The Englishman triumphed after Rosberg, who suffered prolonged power problems with his car, after making a poor start from pole position.

"It was a good start, probably the best start I'd ever had," said Hamilton.

Having started from the prime spot on the grid for the 11th time this year, Rosberg was comprehensively outpaced immediately as Hamilton surged clear to control the race with a well-judged and dominant performance.

Hamilton's victory was his 11th of the season and the 33rd of his record-breaking career and secured a record 16th victory of the season for the Mercedes team.

Rosberg struggled with a series of problems that hampered his performance, but refused to retire when offered a chance to pit with two laps remaining.

He finished 14th and was lapped by Hamilton who became the fourth British driver to win more than one championship, joining Jackie Stewart, Jim Clark and Graham Hill, the last man to succeed in 1968.

Rosberg was dignified in defeat after failing to emulate his father Keke who won the world title in 1982.

"I'm very disappointed," he said. "All in all, Lewis deserved to win the championship. What happened to me had no impact. It did not change anything so there is no point focusing on that.

"He did just a little bit better than me. The positive is I've been the better qualifier over the last two years and that gives me a good base. I came very close and it is a pity it did not work out. I'm proud to have been here with the team.

"It's been very intense, a very special weekend for me with so much support," he said.

"I still believed for a long time. There was always the possibility that Lewis would get something wrong with his car. I never give up and always push and that's why I wanted to finish.

"It's been an intense battle, but a great battle. I race for battles like that. Lewis has been the best and it has been a great challenge. Most of the time it has been extremely enjoyable."

Hamilton came home 2.5 seconds clear of second placed Felipe Massa of Williams and his team-mate Valterri Bottas, who was third.

It was confirmation for Williams that they had taken third place in the constructors' championship ahead of Ferrari.

The result gave Williams two cars on the podium for the first time since the 2005 Monaco Grand Prix.

It was Bottas's 17th points-scoring finish in 19 races and Massa's best result since he finished second at the 2012 Japanese Grand Prix.

Australian Daniel Ricciardo was fourth for Red Bull ahead of 2009 champion Jenson Button, in what may be his last race with McLaren, Nico Hulkenberg and his Force India team-mate Sergio Perez.

Four-time world champion Sebastian Vettel finished eighth in his final race with Red Bull, one position ahead of the man he replaces at Ferrari next season, two-time champion Fernando Alonso and Kimi Raikkonen in the second Ferrari.