Vettel fastest again

Incident-packed free practice session

Formula One world champion Sebastian Vettel limbered up for a Japanese Grand Prix that could bring him a fourth successive title on Sunday with the fastest time in Friday practice.

The German, who will wrap up the championship if he wins on Sunday and Ferrari's Fernando Alonso fails to finish in the top eight, lapped with a best time of one minute 33.852 seconds in an afternoon session with plenty of incidents.

Alonso ended the day with sixth and 10th places on the two timesheets. While Vettel steered clear of trouble, Lotus's Kimi Raikkonen, Pastor Maldonado for Williams and McLaren's Sergio Perez all went off in the afternoon.

Perez's crash was the hardest, with the Mexican slamming sideways into the barriers at the Spoon curve, while Raikkonen went into the gravel half an hour from the end of practice but was still fourth fastest.

Vettel was 0.611 off the 2008 champion's pace in the morning. His Australian team-mate Mark Webber, using a new chassis after retiring at last weekend's Korean Grand Prix with his Red Bull car in flames after being hit by Force India's Adrian Sutil, was second fastest in 1:34,020.

Vettel has won three of the last four races at Suzuka.Ferrari's Brazilian Felipe Massa, runner-up at Suzuka last year, was faster than Alonso in both sessions.

The main morning incidents came from those well down the pecking order, with Venezuelan Maldonado parking up at Spoon when his left rear wheel came off and bounced away.

Maldonado then went into the barriers in the afternoon at Degner. Williams fined Williams were fined 60,000 euros (on Friday after a wheel came off Pastor Maldonado's car during practice.