Novak Djokovic is starting to realize what an impact he's making on tennis with his recent domination of Rafael Nadal - and everyone else in the game, too.

Djokovic beat the top-ranked player 6-4, 6-4 in the Italian Open final in Rome on Sunday to stretch his unbeaten start this year to 37 matches.

Djokovic trails only John McEnroe's 42-0 start in 1984. Overall, the Serb has won 39 consecutive matches stretching to Serbia's Davis Cup triumph in December. It's the sixth-best streak in the Open era, seven behind Guillermo Vilas' record set in 1977.

"It's an incredible honor to be a part of tennis history in some way and part of an elite group of players - (Roger) Federer, Nadal, McEnroe, (Ivan) Lendl, guys who were winning so many in a row," Djokovic said. "I don't know how much good it brings to tennis, but it's good that someone else is able to win other than just Federer and Nadal. It makes it more interesting."

The second-ranked Djokovic has beaten Nadal in the four finals they've played this year and defeated the Spaniard for the first time on clay last week in the Madrid Open final.

This win makes Djokovic the first player to beat Nadal on clay twice in the same year, a feat that comes exactly a week before the French Open starts.

Nadal said it's "impossible" for Djokovic's streak to last forever.

"I have to wait for my moment to win and I know that," the Spaniard said.

In the women's final, Maria Sharapova stormed to a 6-2, 6-4 victory over Sam Stosur for the biggest clay-court title of her career.

Andy Roddick pulled out of the doubles final because of a right shoulder injury.

The Italian tennis federation says Australian Ken Rosewall was admitted to the stroke ward of a Rome hospital. Rosewall's wife, Wilma, told Australia's Sydney Morning Herald the 76-year-old eight-time Grand Slam champion had no heart or brain damage.