Marlboro Yamaha men on rows two and three at Rio.

Marlboro Yamaha Team riders Carlos Checa and Max Biaggi battled throughout this afternoon's torrid final qualifying session, ending the day seventh and tenth quickest, giving them starts from the second and third rows. The session was a thriller, with no less than seven changes of pole position during the hour, and such was the intensity of competition that Biaggi went quickest with seven minutes to go, only to slip nine places down the order over the remaining few minutes.

"The track was very busy and most of it came down to who got a clear lap," explained Marlboro Yamaha Team manager Geoff Crust. "There was only 0.89 seconds separating the top 13 guys at the end, so all it took to lose a bunch of places was to get blocked by someone through one turn. Carlos had a lot of problems with slower traffic but he kept at it and made it on to the second row. His times are consistent too, so he should be able to fight up front tomorrow. Max has been struggling to find a balance that works over all the bumps. It's so bumpy here and if you get knocked off your line through one or two turns, that's the lap effectively gone. Turn one is the worst - it looks horrific, it's so bumpy that the riders are doing well just to keep their feet on the 'pegs."

Tomorrow's Rio Grand Prix is a historic event, bringing to an end 53 years of 500 GP racing. The race is the 580th and last 500 World Championship race before bike racing's premier championship changes for the future, with up-to 990cc four-strokes contesting the MotoGP series from next season.

Carlos Checa was second in this morning's 'free' session but was unable to find a clear track to allow him to repeat that performance in the afternoon's all-important final qualifier. The Marlboro Yamaha Team man ended up seventh for a second-row start, and is feeling confident about tomorrow's race.

"I feel comfortable on the bike here, we've got it working well over the bumps," said the Spaniard, who had been sixth in yesterday's opening qualifying session. "I did my best lap at the end with race tyres, so that makes me confident that I can run a good pace over race distance. The problem today was that there weren't any blue flags shown to tell the slower riders to move out of the way. I got held up by several different guys and I didn't see one blue flag."

Max Biaggi was looking good to repeat his pole position from last year's Rio GP until his final qualifying run went awry. The Marlboro Yamaha Team man had shown his potential by slotting in the fastest time on race tyres, but when he fitted a soft rear for his last outing, he ran into chatter problems. Biaggi has had more success than anyone in qualifying this year - he's scored seven pole positions and hasn't been off the front row since May's French GP. This will be his first start of the season off the first two rows.

"When I went to pole I was running race tyres, so that made us quite confident," said the Italian. "But the soft tyre we fitted for my final run gave us some chatter, so there was no way I could push any harder. We've got a few different ideas to try during tomorrow morning's warm-up session, and if they work well, and if I get a good start, then I hope to be able to fight in the leading pack."