PHOTOS: Sebastian Vettel takes fourth win in a row

Red Bull's Sebastian Vettel completed a hat-trick of Korean Grand Prix victories on Sunday to put himself only one week away from potentially clinching his fourth successive Formula One title.

The 26-year-old's third successive Korean win, and eighth triumph in 14 races, left him 77 points clear of Ferrari's Fernando Alonso with five races -- and a maximum 125 points -remaining.

If the German wins in Japan next weekend, and Alonso fails to finish in the top eight, the championship will be over.

"That was a very, very disciplined drive. Well done," team principal Christian Horner told him over the radio after taking the chequered flag. Vettel replied with his customary whoop of delight.

Alonso could manage only sixth place on an overcast afternoon that threatened rain without delivering. The Spaniard now has 195 points to Vettel's 272.

In a race that exploded into action, with two safety car periods including one that started with the bizarre appearance of a fire marshals' 4X4 on track at the front of the field, Vettel celebrated his fourth victory in a row.

Finland's Kimi Raikkonen finished second, ahead of Lotus teammate Romain Grosjean, in a race that began as another display of Vettel's domination before jolting the audience awake with a bang.

McLaren's Mexican Sergio Perez brought out the first safety car with the explosive delamination of his front right tyre that left a strip of tread lying in the middle of the track.

When that safety car came in, after the debris had been cleared, Vettel's Australian teammate Mark Webber was hit by Adrian Sutil's Force India at the re-start.

The Australian pulled over with his car on fire, for the second race in a row.

With marshals putting out the blaze with extinguishers, the 4x4 appeared on the track ahead of the field between turns one and two and with its hazard lights on while the official Mercedes SLS AMG safety car brought up the rear.

"It's not great getting stuck behind the safety car but I'm really pleased with the result," said Vettel, whose podium appearance at the sparsely-attended Yeongam circuit met none of the booing that had marked the previous three races.

"Fortunately we had enough pace to get ahead after both safety cars but both Kimi and Romain were very competitive and did better with their tyres," he added.