YEONGAM, South Korea (AP) -- Red Bull driver Sebastian Vettel's relentless push toward a seemingly inevitable fourth-straight Formula One drivers' championship continued with a victory at the Korean Grand Prix on Sunday.
Even two safety-car periods, the emergence of a truck on the circuit mid-race and the incineration of his teammate's car were not enough to put off the German, who made it a hat-trick of wins in Korea, and a fourth successive victory overall.
The Red Bull ace led throughout to win by 4.2 seconds ahead of the Lotus pair of Kimi Raikkonen and Romain Grosjean.
Nearest title rival Fernando Alonso was sixth, stretching Vettel's lead in the championship to 77 points with only five races remaining, meaning he could wrap up the title at next weekend's Japanese Grand Prix at Suzuka.
If Vettel wins in Japan, and Alonso finishes worse than eighth, the German will join his compatriot Michael Schumacher and Juan-Manuel Fangio as the only men to win four successive titles.
''Even though it looks very good for us, it's still not over,'' Vettel said. ''I'm not trying to think about it to be honest, I'm focusing more on the present.
''I am really enjoying things at the moment, we have a great team and we are having a great time as well.''
Sauber's Nico Hulkenberg put in a superb defensive drive over the last 17 laps by holding off a queue of world champions behind him after the second safety-car period ended, finishing fourth to equal his career best.
Mercedes driver Lewis Hamilton was fifth, just holding off Alonso on the last lap. Mercedes' Nico Rosberg took seventh by passing eighth-placed Jenson Button of McLaren in the closing stages.
Ferrari's Felipe Massa was ninth and McLaren's Sergio Perez rounded out the top ten.
Vettel, who has now led after every lap of four-straight races, again got away well from pole position and avoided the chaos on turn three, at the exit of the main straight. Massa spun and made contact with teammate Alonso, who was able to continue, while Button and Force India's Adrian Sutil also had collisions that forced them to pit.
Vettel led Grosjean by 2.1 seconds after the first lap but he was not able to pull away from the field as comfortably as he had in recent races, with the Frenchman clinging on and within 3.4 seconds when the leaders started to pit after nine laps.
The championship leader extended that to 5.1 seconds by mid-distance from Grosjean, who had ably held off Hamilton in their battle after the first stops.
Hamilton's rubber soon started to degrade and he fell back toward teammate Rosberg, but as soon as the German passed the Briton, his front wing failed and drooped to the ground, leaving Rosberg driving in a sea of sparks.
The safety car emerged on lap 31 following a spectacular tire failure on the front right wheel of Perez's McLaren, with the tread suddenly shearing off and landing in the middle of the main straight.
The racing had only resumed for a lap when Force India's Adrian Sutil spun into the Red Bull of Mark Webber at the end of the main straight, causing the Australian's car to burst into flames.
With the safety car only having just come in, the field rounded onto the straight at full speed on the next lap only to see a fire marshall's truck trundling down the track toward the fire, acting as a de-facto safety car before the real one could take up the job.
''It looked like a BMW. I think it was a Hyundai or Kia SUV. You want the number plate?'' joked Vettel.
In the one lap between the two yellow-flag periods, Raikkonen had got past Grosjean, but the Finn was unable to keep up with Vettel upon resumption, trailing by 1.4 seconds after one lap and consistently losing time from then on.
Grosjean said the two safety-car periods helped Vettel, suggesting that without them, the two Lotus cars would have been able to manage their tires better over a long last stint and challenge the leader.
''It seems that every time there will be a battle with Seb, there's a safety car coming,'' Grosjean said.
''The last stints would have been pretty epic without the safety car ... it would have been close.''