Sebastian Vettel in ominous form during practice for Indian Grand Prix

Sebastian Vettel in action this in India (GETTY IMAGES)

Sebastian Vettel is threatening to make it four race victories in a row after sweeping Friday practice for Sunday's Indian Grand Prix.

The opening two 90-minute sessions are rarely an indicator as to how a weekend might unfold, but on this occasion and at this stage of the season, Red Bull and Vettel appear unbeatable.

Following a run of three successive wins, Vettel heads into the race at the Buddh International Circuit on the outskirts of New Delhi with a six-point cushion over Ferrari's Fernando Alonso.

There is every possibility that lead will be extended should Vettel maintain his current form, because other than team-mate Mark Webber, the rest of the field were effectively nowhere.

Vettel cruised around the 5.125-kilometre circuit in a time of one minute 26.221 seconds, 1.4secs up on his best in the morning courtesy of the much faster softer tyres that were not aired until FP2.

Webber was just over a tenth of a second adrift, and whilst Alonso was third-quickest, the Spaniard in his Ferrari was 0.599secs down on Vettel, and clearly faces an uphill battle to mount any kind of challenge this weekend.

Just four other drivers finished within a second of Vettel, who is on course to win his third successive title, a feat only achieved previously by Juan Manuel Fangio and Michael Schumacher.

Nico Rosberg in his Mercedes was 0.801secs down, followed by Lotus' Kimi Raikkonen, the Finn a further eight-thousandths of a second behind.

As for McLaren, who have only managed to get both cars home in two of the last seven races to wreck their drivers' title bid and undermine their hopes of a long-overdue constructors' crown, Lewis Hamilton and Jenson Button were left trailing.

Hamilton finished 0.910secs down and Button 0.961secs adrift, with their form of just a few races ago when they had the advantage in Belgium, Italy and Singapore having disappeared.

Behind the leading players, Nico Hulkenberg in his Force India was the best of the rest in eighth place, three places and seven-tenths of a second quicker than team-mate Paul Di Resta.

Sandwiched in between the duo were Romain Grosjean in his Lotus and the Williams of Bruno Senna, the Brazilian faster than team-mate Pastor Maldonado by 0.8secs even after missing out on FP1 to again make way for reserve Valtteri Bottas.

After also missing the first session due to a cold, Sauber driver Sergio Perez returned for FP2 to finish 12th, two seconds behind Vettel, but ahead of team-mate Kamui Kobayashi in 16th.

Bringing up the rear was Charles Pic for Marussia. The Frenchman was 5.272secs behind Vettel.

PA