Jenson Button completed the perfect opening day at the Japanese Grand Prix, but knows that he cannot rest easy as Red Bull Racing appeared streets ahead of the field on race pace.
Although a drop in temperatures midway through the 90-minute afternoon session prevented anyone from threatening the Briton's time - which was over 1.5secs faster than his morning pace - it was the relative performance of the teams on longer runs that will hang over the paddock until Saturday, as Red Bull again looked to have the upper hand when it really matters.
Button's time was set on the soft Pirellis, the option tyre this weekend, and his 1min 31.901secs best was 0.174secs better than anyone else could manage, but the McLaren driver was unable to match anything that RBR's Sebastian Vettel and Mark Webber produced on the harder medium compound, suggesting that the #1 team will continue to be just that on Sunday.
Having topped the morning session, Button briefly led the way in FP2 before having to respond to challenges from Ferrari and Red Bull, as Fernando Alonso, Felipe Massa and Webber all took turns to occupy top spot. Having returned to P1, however, Button benefited from a nine-degree slump in temperatures that denied everyone else a meaningful shot at deposing the McLaren, and ended the session comfortably ahead of Alonso, with Vettel putting in a mid-session run to climb up into third, ahead of his team-mate, with the second Ferrari of Massa completing the top five.
The leading quintet were split by just 0.547secs, with sixth-placed Michael Schumacher eight tenths off Button's pace, and Lewis Hamilton, in eighth, over a second adrift after failing to find a clean lap when the track and temperature were at their best. Nico Rosberg, in seventh, Vitaly Petrov and Sebastien Buemi - respectively keeping Renault and Toro Rosso in the leading group - rounded out the top ten.
With the cooler temperatures reducing traction, several drivers were caught out and took to the scenery with varying degrees of disaster, While Schumacher and Senna got away with incidents at turn one - the Brazilian thoughtfully keeping his engine running after a DRS-induced spin into the gravel, there was a near miss for Kamui Kobayashi and a heavy impact for Rubens Barrichello. The Brazilian put two wheels on the grass entering the Degners and found himself on a one-way trip to the tyrewall, while the local favourite somehow gathered a high-speed moment at 130R, and saved the ensuing tankslapper to boot, to make it back to the pits in one piece.
There were also a series of mechanical malfunctions, notably among the lower reaches of the field, with Pastor Maldonado joining Williams team-mate Barrichello behind the wall at Degner and Tonio Liuzzi parked up on the inside of 130R after his HRT ground to a halt after just a handful of laps. Jarno Trulli was also spotted crawling back to the pits, but was able to rejoin the session after attention from the Lotus crew.