Vettel's (centre) win in Brazil may play into the hands of Alonso (right)
Ferrari's Fernando Alonso is "100%" confident of landing the Formula 1 drivers' title in the final race of the season, in Abu Dhabi on 12 November.
The Spaniard is eight and 15 points clear respectively of Red Bull drivers Mark Webber and Sebastian Vettel.
Asked if he thought he could win the title, Alonso said: "100%. I just need to finish second. It doesn't matter who wins in Abu Dhabi if I finish second."
Under F1's 2010 scoring system, a win is worth 25 points, with 18 for second.
Alonso saw his lead in the standings cut by three points after finishing third in Sunday's Brazilian Grand Prix behind Webber and race winner Vettel.
Webber's second place in Brazil means he has 238 points to Alonso's 246 and if the Australian were to win the final race of the season with Alonso second, then the Ferrari driver would secure his third world title by a single point.
Vettel goes into the final race of the season on 231 points and if he wins Alonso can then finish as low as fourth and still be guaranteed to come away with the title, even if Webber finishes second.
The situation has focussed the mind of Ferrari team principal Stefano Domenicali.
"We know what we have to do and we will prepare everything with maximum attention to detail," he said.
"We don't have to make a very difficult calculation.
"We know if we are in the middle of the two Red Bulls, it's fine.
"We need to make sure we are fast, that we do a perfect qualifying which is very important, fundamental."
If the Red Bulls had employed similar tactics at Interlagos to those
used by Ferrari earlier in the season in Germany,
only victory in the Middle East would have been enough to guarantee Alonso the title.
After what appeared to be coded instructions from the pit wall in July, Alonso's team-mate Felipe Massa allowed the championship leader to pass and take victory at Hockenheim - a move that attracted a $100,000 (£65,100) fine.
In contrast Red Bull, who have insisted throughout the season that they treat their drivers equally whenever possible, allowed Vettel to take victory at Interlagos.
Alonso passes Massa in German GP
However, the German has hinted that
if his title challenge falters in Abu Dhabi he will drive in support of Webber.
Although he would like a sixth victory of the season to seal the title, Alonso knows he has a second option available to him.
"The main goal for us is to be on pole on Saturday and then win the race on Sunday," he said.
"If we cannot do that, if we are not quick enough, then we will try to be second. With that, the problem is finished."
In theory British former world champion Lewis Hamilton can still secure his second world title, but he trails Alonso by 24 points and has conceded it would take a miracle for him to top the standings.