Button sits it out as rain ruins the day.

Byline: Bill Howell

CHAMPIONSHIP leader Jenson Button sat out today's second practice session for the Japanese Grand Prix because he saw no benefit from driving his Brawn GP car around a sodden Suzuka circuit.

Button finished 18th in a damp first session but persistent heavy rain fell throughout the afternoon run, making for difficult conditions with standing water visible in several places on the track.

With tomorrow's qualifying shoot-out and Sunday's race forecast to take place in dry conditions, the Englishman felt there was little value in heading out during the 90-minute window, preferring to concentrate on preparing for what could prove to be the biggest weekend of his career as he looks to secure a maiden drivers' crown.

"We did some wet running this morning, we didn't run in the afternoon because it was very wet and there wasn't any useful running for us to be doing," he said.

"This afternoon was very wet and we decided to call it a day before the end of the session but if you were doing wet running, you would have run at the end of the session for sure.

"You've also got to be careful here because you don't get that many tyres over a race weekend and this place damages tyres quickly.

"It's looking like it's going to be dry for qualifying and the race. At the moment there's not a chance of rain, it can always change for sure, but we'll still be okay.

"We did some set-up work towards the end of the session, running all the info to do with what we're going to do for qualifying tomorrow, gear ratios, that kind of thing. This morning was useful but this place is so much more fun in the dry.'' Team-mate and title rival Rubens Barrichello also failed to emerge on track for the second session having posted the ninth-quickest time in the morning.