Timo Glock enjoyed a fine second practice session on Friday to top the timesheet ahead of this weekend's Japanese Grand Prix.
The Toyota driver clocked a time of one minute 18.383 seconds to edge Renault's Fernando Alonso by 0.043 seconds.
Championship leader Lewis Hamilton, quickest in the opening session of free practice earlier on Friday, finished third with a best lap of 1:18.463.
The McLaren driver's title rival Felipe Massa finished fourth while the Brazilian's Ferrari team-mate Kimi Raikkonen took fifth.
Red Bull's Mark Webber, who only managed to finish 13th in the first session, clocked a time of 1:18.734 to round off the top six.
Home favourite Kazuki Nakajima capped a fine day in his Williams as he improved on his 10th place in P1 to take seventh while Sebastian Vettel of Toro Rosso finished eighth.
Hamilton's teammate Heikki Kovalainen was ninth fastest while Jarno Trulli completed an impressive practice session for Fuji Speedway circuit owners Toyota by finishing 10th.
Red Bull's David Coulthard could only manage 17th while Jenson Button propped up the order by finishing 20th in his Honda.
Conditions were as they were in the first session, remaining dry although the sunshine was occasionally blocked out by cloud cover above the circuit.
After a slow start in first practice the drivers were quickly out this time as Force India's Giancarlo Fisichella recorded the first timed lap three minutes in with 1:24.053.
Alonso stepped up the pace soon after as the Spaniard clocked 1:19.951 to top the order but Hamilton quickly took the lead when he went 0.315 seconds faster than his former team-mate.
The lead then interchanged between a number of drivers as Massa, Adrian Sutil, Trulli and Vettel all had a spell at the top of the timesheet.
But Glock took over the lead just over 30 minutes into the session when he clocked a time of 1:18.383 while Hamilton climbed up to second with a time of 1:18.463 midway through the session.
That was how it remained until the closing stages when Alonso showed good pace with a time of 1:18.426 to go second with five minutes of practice remaining.
However neither Hamilton or Massa, who will resume their battle for the world championship this weekend, were able to better Glock's time on their final lap.