Jenson Button and Lewis Hamilton topped the times after the first practice session at Suzuka.
Hamilton headed the times initially before Button pegged him back with a lap of 1’33.648, less than a tenth of a second faster than his team mate.
With the teams using just one set of tyres there were few improvements later in the session and the McLaren duo remained on top of the times.
One driver who did improve his time was Sebastian Vettel, who took third with a 1’34.090. The Red Bull driver was seen tackling the high-speed 130R without closing his DRS early in the session.
Button found 0.014s with his final lap of the session to cement his place at the top of the times.
But Vettel’s final effort did not go according to plan. He took to the run-off at Degner 2, ploughed through the gravel and reached the barrier at low speed.
Fernando Alonso was fourth for Ferrari ahead of the second Red Bull of Mark Webber.
Pastor Maldonado’s session came to an early end when he went off at turn six. He rejoined the track but pulled over shortly afterwards.
The Toro Rosso pair showed good early pace, Jaime Alguersuari taking sixth, Sebastien Buemi eighth, with Felipe Massa in between them.
Michael Schumacher and Vitaly Petrov completed the top ten.
The Renault driver was running the regular specification bodywork on his car while team mate Bruno Senna evaluated the latest upgrade. He was 11th, a tenth of a second off his team mate.
2011 Japanese Grand Prix
Image © Red Bull/Getty images