Sebastian Vettel's last-ditch attempt to win the Formula One world title today began with an explosive performance in first practice for Sunday's season-ending Abu Dhabi Grand Prix.

Vettel has to finish in the top two to stand any chance of claiming an unlikely championship triumph, bearing in mind he is the only one of the four contenders yet to lead the standings at any stage this season.

The German is 15 points behind Ferrari's Fernando Alonso and seven adrift of Red Bull team-mate Mark Webber, but those two were left virtually standing by Vettel.

The 23-year-old, who won the inaugural race at Yas Marina circuit a year ago, comfortably set the pace as he finished over six tenths of a second clear of Lewis Hamilton.

Astonishingly, in a country that sees precious little rain over the course of the year, practice began with damp conditions. A 20-minute downpour soaked the circuit as the Porsches practised about 90 minutes before the F1 cars hit the circuit.

Despite temperatures of 29 degrees centigrade, the track was still declared wet come the start of the initial 90-minute session. It meant after the customary installation laps, the drivers did not venture out again until the circuit was completely dry.

Vettel then emerged as the one to catch as he set a time of one minute 42.760secs for the 5.554km venue. Hamilton, who was on pole for McLaren 12 months ago, was 0.609secs adrift as he began his search for the miracle that will give him the championship due to the fact he is 24 points down on Alonso.

As for the rest, outgoing world champion Jenson Button was the next of the challengers, but the 30-year-old in his McLaren was a second off Vettel, followed closely by Webber.

Robert Kubica was fifth in the standings in his Enstone-built Renault, followed by championship leader Alonso, who knows he needs only a top-two finish to guarantee himself a third title.

Mercedes and Sauber took up the remaining four slots in the top ten, with Michael Schumacher and Nico Rosberg seventh and ninth for the former and Kamui Kobayashi and Nick Heidfeld eighth and 10th for the latter.