Lewis Hamilton and Jenson Button led a McLaren 1-2 in another wet practice session ahead of the Korean Grand Prix.
Hamilton emerged as the quicker of the pair in a session where drivers elected to spend more time on track, having spent much of FP1 waiting in the garages in the hope of weather conditions improving.
Hamilton's benchmark time of 1min 50.828secs came in the first half of the session with Button slotting into second place and closing to within a tenth of a second of his fellow Brit as conditions allowed drivers to sample the intermediate Pirelli rubber.
The gap between McLaren and the rest was something of a surprise however, with world champion Sebastian Vettel a full 1.8secs behind in third for Red Bull. The German was able to edge Fernando Alonso's Ferrari down to fourth, with Mark Webber and Jaime Alguersuari rounding out the top six.
For Alguersuari, it was a mixed session, with a top six placing being a strong way to show Toro Rosso what he is capable of after he gave up his car for FP1 to allow Jean-Eric Vergne time behind the wheel. However, the Spaniard saw his session end early when he was hit by the Mercedes of Nico Rosberg while exiting the pits after the German slid wide at turn one.
That left Rosberg eight after he was forced to park his car on the side of the circuit, with the Ferrari of Felipe Massa between the Alguersuari and the Mercedes man on the times.
Sebastien Buemi and Paul di Resta completed the top ten.
The session saw a number of drivers run wide or suffer spins in the challenging conditions, including Alonso, Hamilton and Rubens Barrichello.
Buemi meanwhile also suffered a spin having elected to try a run on slick tyres towards the end of the session.