McLaren's Lewis Hamilton threw down the gauntlet to world championship rival Felipe Massa on Friday in opening practice for the Japanese Grand Prix, topping the timesheets.
The Briton's best lap of 1min 18.910secs came with 25 minutes of the 90-minute session remaining, and the 23-year-old was on course for a quicker lap with five minutes left before running wide at the chicane on turn 10.
Ferrari's Massa, who trails Hamilton by seven points in the world title race with three Grand Prix remaining, was 0.153 seconds behind his rival in second despite not completing a timed lap for the first third of the session.
Hamilton's teammate Heikki Kovalainen, reigning world champion Kimi Raikkonen for Ferrari, and Renault's Fernando Alonso, a surprise winner in the last Grand Prix in Singapore, rounded out the top five.
Raikkonen dominated the first half of the practice before Hamilton took top spot from the Finn after 59 minutes.
McLaren and Ferrari filled the top four spots on the timesheets exclusively in the last 30 minutes of the session, which was held under sunny skies after the 2007 race weekend at the foot of Mount Fuji was hit by torrential rain.
The opening session was largely incident-free, with the only yellow flag caused by a gentle spin by BMW Sauber's Nick Heidfeld at turn 10 in the closing stages.
Williams rookie Kazuki Nakajima, the only local in the 20-car field, languished near the bottom of the timesheets for the majority of the session before a flying final lap saw him finish in 10th place.
Toyota's Timo Glock was the busiest man, completing 37 laps. He also ran off the track five times on his maiden visit to Fuji Speedway.