Renault's Alonso singles out Button threat in Australia

World champion Fernando Alonso picked out Honda's Jenson Button as the biggest obstacle between him and winning tomorrow's Australian Grand Prix.

"He never makes mistakes and competes in all circumstances," Alonso told reporters yesterday in Melbourne.

The Spaniard completed 14 laps during the two practice sessions at the Albert Park circuit and only Button of the drivers racing tomorrow clocked a faster time.

Alonso drove well within his limits as he lapped a windy Albert Park circuit in a best time of one minute, 27.443 seconds during the two 60-minute sessions.

With all of the teams adopting a cautious approach to conserve their engines and tyres, the top three times were all recorded by test drivers.

Briton Anthony Davidson set the fastest time of 1:26.822 in a Honda just ahead of Austrian Alexander Wurz in a Williams and Sauber's Polish driver Robert Kubica.

Button set the fastest time amongst the actual race drivers, to be fourth overall, just ahead of Alonso, Germany's Michael Schumacher and Finland's Kimi Raikkonen.

"It's been a positive start to the weekend and so far so good," Button said.

"The circuit had very low grip but we ran through everything we intended and most importantly, it's good that Anthony completed all his test items."

Alonso spectacularly usurped Button as the most promising driver in the paddock when he became the youngest world champion in the sport's history last season at the age of 23.

But Alonso believes Button, who is still winless since making his debut for Williams at Melbourne in 2000 at the tender age of 20, is the closest to him in terms of skill level.

"I think he can do really well and the car is now very competitive. We all saw him in 2004 when he was third behind the two Ferraris, lots of podiums and that showed he has to be a consistent driver.

"But to be the world champion you need something more. You need to win races and be lucky.

"You need to be strong in the important parts of the championship and you need a team that is always developing."

Renault's famed superior starting speed remained, Alonso maintained, but he believes the improved Button would be a difficult prospect to overtake if the Briton can translate his practice form into a front-row grid slot in today's qualifying session.

"Honda are similar to us, close to us. We are the best starters in the paddock still but they have improved a lot from last year.

"It's not nice to have Button in front of you because Honda is starting very well. It will be difficult if Button is in front of me, it will be very interesting."

Schumacher, winner of four of the past six Australian grands prix, survived a brief scare yesterday when he slid his Ferrari onto the grass after running wide on a turn.

"A gust of wind pushed the car from behind when I had no room to brake," he explained.

"Things went pretty well... there were no other problems."

Raikkonen also made an unscheduled off-road excursion in his McLaren but recovered quickly to set the seventh fastest time overall.

"That sometimes happens when you try different things," he said.

"It was still a good start to the weekend."

There were no major casualties in either session although Swiss test driver Neel Jani had to quit the morning session early when he hit a wall in his Scuderia Toro Rosso after locking up his rear brakes.