pbr Sebastian Vettel has taken over the mantle of the youngest world champion in Formula One history following an astonishing end to one of the most dramatic seasons in the sport's 60 years.br ppbr Vettel took the chequered flag in Abu Dhabi for his fifth victory of the year, and with Ferrari's Fernando Alonso a distant seventh as a number of events conspired against him, it allowed the German to make sure of his place in the record books.br ppbr At 23 years and 135 days, Vettel beats the mark of Lewis Hamilton - who finished second in this race ahead of team-mate and outgoing world champion Jenson Button - by 166 days.br ppbr It guaranteed Vettel the title by four points from Alonso, with Red Bull completing a championship double after winning the constructors' crown a week ago in Brazil.