World champion Marc Marquez is expecting a fierce challenge from Valentino Rossi as he tries to extend his record-breaking win-streak at Sunday’s Italian Grand Prix.

Marquez, who became the youngest world champion aged just 20 last season, has won all five of this year’s GPs, despite suffering a broken leg which forced him to miss some pre-season test events.

A week ago, the Spaniard became the first driver to win the first five races of a championship since Giacomo Agostini in 1972 after coming back from 10th place on the first lap to claim victory in France.

The 21-year-old is 42 points clear of teammate Dani Pedros at the top of the championship table with Valentino Rossi a further two points back in third.

But Marquez is expecting a tough battle from the Italian when they race at the seven-time former world champion’s home GP at Mugello.

“In these five races, I had the level but I think, in Mugello, Valentino will be 22 years old again! He will again be so fast and will push a lot,” said Marquez.

“Of course now we are in a very good moment, but we cannot forget we are in the best championship with the best riders. It looks easy from the outside but, inside the pit box, we know how we need to work and we push a lot every practice.”

Marquez suffered his only fall of last year’s championship in Italy in a race that Rossi had dominated for large parts of this century.

The Italian was unbeaten at his home race for seven years from 2002, and doesn’t see Marquez’s 2014 form as a “big problem” for him.