Red Bull boss Christian Horner has said he feels the Abu Dhabi Grand Prix was the key race that helped Sebastian Vettel secure a third F1 title in 2012.

Heading into the race at Yas Marina, Vettel led Fernando Alonso by 13 points but was forced to start from the back of the grid after it was found that his car didn't have enough fuel in to provide a sample to the FIA after qualifying.

Despite the penalty, Vettel produced a storming drive to come through the field to third place - just one spot behind Alonso - to ensure he retained a lead of ten points with just two rounds left to run.

Having then finished ahead of Alonso in the USA to take the lead back up to 13 points, Vettel wrapped up the crown by just three in dramatic fashion at Interlagos.

Speaking to Sky Sports News, Horner admitted that the 2012 title had been the hardest for Vettel to win and said the importance of his result in Abu Dhabi couldn't be underestimated.

"I think that was a crucial race," he said. "Seb had qualified third and was looking in pretty decent shape for that race and then he had to go to the back of the grid and we elected to start him from the pitalne. We were hoping for a top-ten finish to limit the damage to ideally still leave Abu Dhabi with a points lead. We never dreamt he would be on the podium.
He put in a phenomenal drive and I think what he has demonstrated more than anything else this year is that his race craft and his ability to go through a field is second to none.

"Sebastian has fought so hard for this championship and I think that, of the three, this has been by far the hardest. We haven't had a car advantage throughout this year and if you go back to the first race of the season at Australia, he fought on every lap to be on the podium. There have been other races later in the year when he has put in phenomenal drives that have largely gone unnoticed - the fourth positions, the fifth positions - and then, as we have managed to chip away at the performance, he has capitalised on that.

"Putting that run of four successive race wins at the fly-aways from Singapore through to India was a hugely impressive performance. To come back from being forty points behind, it's been quite remarkable to see what he has achieved."

Horner added that Vettel's third successive title, and the fact he is now the youngest triple champion in the history of the sport, meant the German can now be classed alongside some of F1's greats.

"He is a three-time World Champion and has won successive World Championships," he said. "He has raced in 101 races and won 26 of them, he has been on the podium more than 40 times which is almost in fifty per cent of the races he has raced in, and he has 34 pole positions. I think those statistics, plus the way he conducts himself, just absolutely puts him amongst the greats.

"F1 at the moment is going through a halcyon period. Fernando Alonso is a wonderful, massively-gifted driver, as is Lewis Hamilton, and then you have the likes of Jenson Button, Kimi Raikkonen, who has come back this year, and of course Mark Webber, so it's a halcyon period for F1 and to succeed, and achieve the level of success that he has, is quite remarkable, especially as he is only just 25 years of age."