Djokovic could become the world No.1 in the next three weeks.

He said in Rome that his ambition was to be at the top of the rankings and his dream was to win Wimbledon.

How has this newly calm, yet exhilarated Serb, who turns 24 on Sunday, re-invented himself from someone once renowned more for apparent physical frailties and his impersonations of his fellow players to become an outstanding athlete in his own right?

"I don't underestimate anybody, I just want to play my best tennis and win," he said. "In the past I was not able to stay psychologically balanced."

Djokovic has beaten Nadal the past four times they have met, Roger Federer the past three, Andy Murray the past two and won six of his past seven against Robin Soderling.

The game has changed.