All about tactics in Abu Dhabi's F1 finale

Sebastian Vettel made a great start.

If more races had been like the Abu Dhabi Grand Prix, Sebastian Vettel might have been world champion a few races earlier.

The German enjoyed a relatively comfortable day to claim the 10th - and arguably most important - victory of his career.

He led from the start and was only headed during the pit stops, with the result enough to edge out Fernando Alonso's Ferrari and take the drivers' championship by four points.

He won in his Red Bull-Renault because he put in a faultless drive in the fastest car in the field, but he was helped by other factors, namely the early safety car period to clear up the debris from Michael Schumacher's collision with Vitantonio Liuzzi, and also an early pit stop by Mark Webber, his teammate.

Vettel, who had gone into the race knowing that he had to be either first or second to have any chance of being the champion, led from the start from Lewis Hamilton's McLaren-Mercedes.

Vettel initially looked as if he had the pace to pull away once the safety car procession had ended on lap five, building up almost a two-second lead by lap nine.

But then Hamilton began to peg him back, as Vettel had to nurse his tyres as they briefly lost grip.

"The car was phenomenal today," he said.

"It was crucial that I got in front of Lewis at the start. In the first stint I was pulling away but then I had a little bit of graining and Lewis got a bit close but then the car stabilised and it was OK."

The next crucial stage to the race came on lap 25 when Vettel went in for a pit stop. With both Vettel and Hamilton's soft Option tyres beginning to go off, both needed to change them.

The Red Bull-Renault team had been concerned that Vettel did not have the sufficient 20-second gap to take his pit stop and get back out in front of Kamui Kobayashi's BMW Sauber-Ferrari and the Renault of Robert Kubica, who had both started on the harder Prime tyre were due to have a long first stint.

With overtaking difficult Red Bull could not risk Vettel's pace being compromised so Guillaume Rocquelin, Vettel's race engineer, twice came on the radio urging his man to push as hard as he could.

Vettel responded with laps of 1min 44.991secs on lap 22 and 1.44.913 on lap 23, the fastest of the race at that point.

Hamilton took his pit stop on lap 24 and became stuck behind Kobayashi and Kubica, but Vettel made it out fractionally ahead of Kobayashi and he never looked back.

"It helped that Lewis got stuck behind Robert Kubica and that allowed me to open up a gap after my stop," Vettel added.

Hamilton said: "It was just impossible to get past him - he made no mistakes - so it wasn't possible to resume my attack on Sebastian. But that's the way motor racing goes sometimes."

Vettel retook the lead when Button finally took his pit stop on lap 40 and he was able to cruise to his second successive victory following his win in Brazil last weekend.

He was still left for a few seconds to wonder if it would be enough to take the title. In the end it was.

That was thanks firstly to the safety car period which allowed six cars, including Nico Rosberg's Mercedes GP and Vitaly Petrov's Renault, to make a pit stop and change on to the Prime tyres.

Essentially they had a free pit stop, not losing the usual 20 seconds as the other drivers were running behind the safety car.

These drivers came into play when Webber, who had been struggling on the Option tyres, was pitted early by Red Bull on lap 12 after he had suffered a scare when he brushed the wall at Turn 19 on lap nine.

He had been running behind Alonso and Ferrari, concerned about the Australian leapfrogging the Spaniard in clean air and with new tyres, made the fateful decision to bring in the championship leader after seeing Webber set the fastest first sector of anyone on lap 15.

The double world champion came in on lap 16 and only just stayed ahead of Webber. The bad news was that he had fallen behind Rosberg and Petrov, who did not need to stop again.

Alonso, despite his best efforts and some arguably patronising encouragement from his pit wall, was unable to pass Petrov and was doomed to finish seventh.

Webber acknowledged that his early stop forced Ferrari to switch their strategy.

"Going for the harder tyre pretty early obviously hurt Fernando because he had to cover me off, so in a way it was a bit of a team effort I suppose," he said.

Alonso had been close behind Button at the time of the stop and if he had stayed out rather than taking his pit stop he could have been fourth, which would have given him the title by two points.

After all the talk in the build-up to the race of Vettel's aiding Webber title challenge, it was ironic in the end that it was an act by Webber that helped win the championship for his teammate.