ROME, May 10: World number one Roger Federer's dreams of winning his first Rome Masters title ended when he slumped to a 6-2 6-4 defeat against Italian wild card Filippo Volandri in the last 16 on Thursday.

Third seed Andy Roddick also fell, losing 6-0 6-4 to Argentine claycourt specialist Juan Ignacio Chela.

Fourth seed Nikolay Davydenko progressed, however, with a 4-6 6-2 7-5 win over Potito Starace.

Defending champion and world number two Rafael Nadal will be aiming to extend his 73-match winning streak on clay when he meets 15th seed Mikhail Youzhny in a later match.

Federer, who finished runner-up in Rome in 2003 and 2006, never found his rhythm against Volandri, dropping serve three times on the way to surrendering the first set.

He rallied briefly at the start of the second set, but four errors in the third game -- the last two a long backhand and another into the net played almost casually -- allowed Volandri to grab another break and serve out for the match.

Federer's defeat means he has gone four tournaments without a title, his longest stretch since becoming world number one in February 2004.

“It's disappointing, but there's nothing you can do about it. That's knock-out tennis,” said a downcast Federer, denying he was ill or injured and dismissing the heat on Rome's centre court as a contributing factor to his defeat.

“I played good in my first match (to beat Nicolas Almagro), and usually after the first game I play better and better, but today was the opposite. On clay you need to be solid, and I wasn't. I don't know if you can say I was playing shockingly, but I was making a lot of mistakes, serving badly -- giving him second serves all the time.

Volandri, who has slipped back to 53rd in the world rankings after finishing last year inside the top 40, could hardly believe his win, which sent him through to a quarter-final against 12th seed Tomas Berdych after the Czech brushed aside Jose Acasuso 6-1 6-2.

“I played the match of my life and pushed all the way to the end. I couldn't ask anything more of myself,” he said.—Reuters