Jenson Button confirmed that McLaren's pace from the opening day of the Korean Grand Prix would carry over into dry running after topping the third and final free practice session of the weekend in Yeongam.
The Briton defied a change of chassis - the result of a broken engine mount on his original - to record a 1min 36.910secs effort on his final lap to pip McLaren team-mate Lewis Hamilton to top spot by a couple of tenths, but both drivers will be wary of the usual threat from Red Bull after Mark Webber slotted into third and newly-crowned world champion Sebastian Vettel saw a potentially faster lap ruined by a stubborn Jaime Alguersuari.
Button, too, had reason to thank Michael Schumacher, after the seven-time champion gave Hamilton another warning that he would not yield easily, chopping the Briton as he looked for a way through on what could have been a better lap. While Hamilton still managed second place, however, Vettel found himself down in an inconclusive ninth spot, and remains an unknown quantity when it comes to qualifying.
If the German's pace is a match for Webber's - which it usually is and more - he could still fall into the eight-tenths of a second gap that opened up between the Australian and Button, as the teams made the most of the first dry running of the weekend by completing a lot of laps. Webber and Vettel were among the busiest men on track, completing 23 and 22 laps respectively - the McLarens completed 18 apiece - but neither could match the effort of Nico Rosberg, who covered 25 tours as he attempted to make up not only for the wet conditions on Friday, but also the time he lost following his collision with Alguersuari in FP2.
Between Webber and Vettel, Fernando Alonso and Felipe Massa suggested that Ferrari would again be the third leg in the lead battle, although the Spaniard lapped over a second off Button's pace, while Schumacher, Vitaly Petrov and Adrian Sutil all made the most of Vettel's hold-up to slot in ahead of the German. The hard-working Rosberg rounded out the top ten, fully 2.8secs off the pace, with the usual Force India, Sauber and Toro Rosso battle squabbling for the next few places.
Bruno Senna would up down in 16th after a tankslapper, caused by a wheel dropping onto still-wet artificial turf, spun the Renault lightly into the retaining wall and damaged the front wing, while rookie Daniel Ricciardo, in need of as much track time as possible on his first visit to the Korea International Circuit, suffered a radiator leak and managed just eleven laps in the hour. Jarno Trulli, who sat out FP1 in favour of Karun Chandhok, also completed fewer laps than he would have liked, with just 13 in the books, but the Italian still managed to put his Lotus ahead of the Virgin and HRT entries.