Yeongam: Lewis Hamilton kept Ferrari's Formula One championship leader Fernando Alonso off the top of the timesheets in Friday's first free practice for the Korean Grand Prix.
McLaren's Hamilton needs a win on Sunday to get back into a title fight that looks increasingly like a duel between Alonso and Red Bull's Sebastian Vettel, and the Briton lapped the dusty Yeongam circuit with a best time of one minute 39.148 seconds.
Alonso, four points clear of reigning champion Vettel with five races remaining, was 0.302 slower with Red Bull's Mark Webber third fastest ahead of Ferrari's resurgent Felipe Massa.
Vettel was fifth fastest while Lotus's Kimi Raikkonen, having his first taste of the track some 400km south of Seoul due to his absence from Formula One for the past two years, ended up 11th.
The Finn was trying out a new 'Coanda' exhaust system that his team hope will bring big benefits in the closing races as they battle Ferrari for third place in the constructors' standings.
With the circuit little used for most of the year, drivers took their time setting fast laps as they waited for the surface to clean up.
Alonso, who was pitched out at the start of last Sunday's Japanese Grand Prix, was an early pacesetter with Hamilton faster towards the finish.
McLaren's Jenson Button was 10th fastest at a track he described on Thursday as: "Monza for the first 45 seconds of the lap, then a mid-high-speed section, quite flowing, and then you've got driving around your living room at the end of your lap."
Finland's Valtteri Bottas took Brazilian Bruno Senna's place for the session at Williams while French reserve Jules Bianchi came in for Nico Hulkenberg at Force India and was 13th.
Other less familiar faces for the morning were Dutch tester Giedo van der Garde for Russian Vitaly Petrov at Caterham and Spaniard Dani Clos replacing Indian race regular Narain Karthikeyan at HRT.