By Paul Virgo

ROME (Reuters) - A ruthless Rafa Nadal showed he was primed to win back his beloved French Open crown from Roger Federer when he whipped Germany's Philipp Kohlschreiber 6-1 6-3 in his opening match at the Rome Masters.

Federer was adamant his Rome setback on Tuesday would have little impact on his chances of defending his Roland Garros crown as he still had a month to find his best tennis before the claycourt major.

But Nadal fired an early warning that he was once again ready to trample over anyone who stands in his way on his favorite surface after knee problems disrupted his 2009 season.

"Please don't compare me with Roger because Roger has lost very few matches in his career," the Spaniard told a news conference. "I just do my best and one day I'm going to lose, perhaps tomorrow, although I hope not."

Nadal's second-round display was not flawless by any means but that provided little consolation for Kohlschreiber.

The four-times French Open winner had it all his own way in the first set, when Kohlschreiber did not help his cause with some wild forehands.

The German put up more resistance in the second set and had a break point in the sixth game.

But Nadal stood his ground before breaking serve twice to wrap things up and set up a third-round meeting with Romanian Victor Hanescu.

"I did well. I played safe. I played focused all the time," he added. "My serve was working well. I worked well from the baseline and I felt good.

"Philipp is a tough opponent and to play against him in the third round was a challenge for me. I am very happy about my victory."

Swedish fifth seed Robin Soderling, who handed Nadal his first ever defeat at the French Open last year, is on course to meet the Spaniard in the quarter-finals after dispatching Italian wild card Paolo Lorenzi 6-1 7-5.

Federer gained some consolation for Tuesday's defeat with the help of his compatriot Yves Allegro, beating the Swedish-Australian pairing of Simon Aspelin and Paul Hanley 4-6 6-3 10-8 in the doubles.

(Editing by Miles Evans)