Lorenzo convinced he will be champion

The Spaniard has won the 250cc title in 2006 and 2007 and will now make his MotoGP debut as Valentino Rossi's teammate at Yamaha.

"I'm convinced one day I'll win the MotoGP title," Lorenzo told AS newspaper. "I don't know when, but it's on my mind and I feel it's something almost certain.

"But it's impossible to be sure that I'm going to get it on my first year. No one can feel as confident as Stoner right now, because he's the champion and he has a shockproof frame of mind.

"I believe there's nothing impossible, but it's not enough to say it, you have to do it."

The 20-year-old says his previous titles mean a lot to him, but he admits racing in the top category is what is all about.

"The two 250 titles have been good," he added. "To me they mean a lot because I have achieved more titles than important people like (John) Kocinski or (Tetsuya) Harada, or the same as (Luca) Cadalora and someone else.

"That's a lot, but as Marcos, my trainer, says, now it's when everything begins for me because in MotoGP you have the best of all, Valentino Rossi, and he's surrounded by the best in the sport. Now it's the moment of truth."

The MotoGP season begins this weekend in Qatar, which host the first night race in history.