Red Bull's Sebastian Vettel dramatically crashed out in practice on Friday in a jittery start to the Japanese Grand Prix, where he is just one point away from sealing back-to-back world titles.
The German speared into the wall at turn nine in the final minute of opening practice, but he was unhurt in the smash. Vettel was third in the session and McLaren's Jenson Button was quickest with 1min 33.634secs in his last lap.
Button, who sits second in the championship and trails the German by 124 points, needs to win the final five races of the season and have Vettel not finish better than 10th in any Grand Prix to deny him the title.
Vettel's car sustained only minor damage in the nose-first plunge into the barriers, with Red Bull expected to set a new front wing assembly before the afternoon practice session.
Splitting Button and Vettel in opening practice was Briton Lewis Hamilton, the McLaren driver finishing 0.091secs behind his team-mate.
Spain's Fernando Alonso was fourth for Ferrari, while Vettel's team-mate, Australian Mark Webber, rounded out the top five.
Ferrari duo Alonso and Felipe Massa of Brazil were the first drivers from the top-line teams on the circuit on a sunny morning at Suzuka, but it was Webber who made the early running as he went fastest with his first timed lap.
Alonso and then Hamilton quickly usurped Webber's time before Button edged his team-mate by seven one-hundredths of a second with a 1:33.468 after 45 minutes, which remained the time to beat until his final lap of the session.
Besides Vettel, Venezuelan Pastor Maldonado was the only other driver to run off-track and finished the session in 18th place, completing just eight laps in all.
The 26-year-old Williams rookie, a first-time visitor to Suzuka, ran wildly off the circuit at turn six midway through the 90-minute session and was forced to park the car beside the track.
German Timo Glock also had his session curtailed; the Virgin driver managed just 13 laps and finished 21st after spending much of practice in the pits with gearbox problems.