Kimi Raikkonen edged out Sebastian Vettel to finish quickest in the second practice session for the Malaysian Grand Prix.
The Lotus Renault driver, who won the Australian Grand Prix last weekend, finished just 0.019s ahead of his title rival's Red Bull in Sepang.
Ferrari's Felipe Massa finished less than a tenth of a second behind the front two, while teammate Fernando Alonso recorded the fourth fastest time.
Force India's Paul di Resta was the quickest out of the four British drivers after he finished in eighth, with Lewis Hamilton's Mercedes a place behind in ninth.
Jenson Button continued to struggle in his McLaren, ending the session in 12th place.
