Valentino Rossi says he cannot take his MotoGP championship lead for granted as he expects a stern challenge from title rival Jorge Lorenzo at the Australian Grand Prix.

The factory Yamaha rider heads to Phillip Island this weekend with an 18 point lead as he closes in on a 10th world title and his first since 2009.

Rossi has proved to be a dominant force at Phillip Island with six premier class wins to his name marking him as a strong favourite for Sunday’s race.

Although in the box seat to secure a popular title triumph, the 36-year-old remains wary of the threat from his team-mate Lorenzo.

Phillip Island could prove crucial in the title race as the championship heads to Malaysia later this month before the final round at Valencia on November 8.

“Eighteen points can be a good advantage but it can also become a very small advantage,” said Rossi.

“We have three races but now we have this track that I like very much.

“It’s always a good result and great memories here in the past but as always all the rivals are very strong, especially Jorge who is very fast here.”

Meanwhile, Lorenzo has his eyes firmly focussed on victories in the final three rounds as he bids to reel in Rossi.

The double world champion has shown speed at the Phillip Island track after recording victory in the 2013 Australian Grand Prix.

“Obviously now it comes to the final three races in the championship and we must win a lot if we want to recover the points and have the chance in Valencia to be World Champion,” said Lorenzo.

“The championship is the goal we have, but we are not very focused on the result just to keep working in the same way on the bike, on the setting and on my riding and if we keep working like that we are going to be fast and consistent.”