World number one Novak Djokovic hopes momentum is still with him as he launches his clay court season at the Monte Carlo Masters where champion Rafael Nadal is aiming for an eighth consecutive title.

The Serb is chasing Nadal's French Open crown after winning the last three major events.

Djokovic has beaten Nadal in their last seven meetings, including the Madrid and Rome Masters finals in what were the Spaniard's only two defeats on clay in 2011.

"The momentum turned but in the last couple of years it was Nadal and Federer who were coming (out) on top. This is something that happens on this level, the momentum changes," a cautious Djokovic told a news conference on Sunday.

"Nadal is the ultimate challenge on clay," he added. "He's the king of clay, the best tennis player ever to play on this surface... The fact is that Nadal plays his best tennis in Monte Carlo aside from Paris. He won seven times."

Djokovic, who like Nadal has a bye into the second round, could face a tough test in the quarter-finals with a clash against world number six David Ferrer, last year's finalist.

In the semis, he could meet Andy Murray, who reached the last four in Monte Carlo, Rome and the French Open last year.

"We played an unbelievable match (last year) in Rome," Djokovic said of the third set tie-break the Briton forced him to in Italy.

"I think he improved a lot on clay. He can spin the ball more, he always has the great serve."

Nadal potentially has an easier path through to the final with a possible quarter-final against fellow countryman Nicolas Almagro, then a semi with Frenchman Jo-Wilfried Tsonga.