JOIN USSebastian Vettel led a Red Bull one-two on Friday in free practice for a South Korean Grand Prix that could send the Formula One world champion back into the overall lead for the first time since the fifth round.
The 25-year-old German, four points behind Ferrari's Fernando Alonso with five races remaining, set the fastest lap of a clear and sunny day in the afternoon session with a best time of one minute 38.832 seconds.
Australian team-mate Mark Webber, who lined up with Vettel on the front row of the grid in Japan last Sunday in a race that the German won from pole, was a mere 0.032 slower after being third fastest in the morning.
Alonso was third quickest in the second session, 0.328 off Vettel's pace but with a more competitive looking Ferrari. McLaren's Lewis Hamilton had kept Alonso off the top in the morning with a best effort of 1:39.148. The 2008 champion was eighth fastest after lunch at the dusty circuit some 400km south of Seoul.
Hamilton needs to deny Vettel, last year's winner in Korea, a third win in a row on Sunday to get back into a title fight that looks increasingly like a duel between Spaniard Alonso and the Red Bull champion.
Lotus' Kimi Raikkonen, absent from the first two Korean Grands Prix due to his switch to rallying, had his first taste of the circuit and was 11th and 10th respectively in the two sessions.
With the circuit little used for most of the year, drivers took their time setting fast laps when the first session opened.