McLaren's Jenson Button had a successful practice in Japan, topping the timing sheets in both sessions.
The Englishman finished ahead of teammate Lewis Hamilton in first practice and Ferrari's Fernando Alonso in the second session.
Button, 31, is currently leading the chase for second place in the world championship, with the title all but sewn up for German Sebastian Vettel.
The Red Bull driver recovered from an early crash in the first session at the Suzuka Circuit to finish third in both sessions.
Vettel, who has won the last two Japanese Grands Prix, can still mathematically lose the world title but he needs to not score another point in the whole season while Button must win every race.
Sunday's race begins at 7am.
