Back-to-back Ricco

Ricco won in Macerata on Friday with an attack on the uphill finish and repeated the strategy to win the 158-km fourth stage from Pievebovigliana to Offagna near the Adriatic coast.

The 23-year-old finished four seconds ahead of Germany's Stefan Schumacher and Alexandre Vinokourov of Kazakhstan, and took the overall race lead from Russia's Alexandr Arekeev.

He now leads Vinokourov by 16 seconds, with Schumacher third at 20 seconds.

"I'm in great form and I think I showed I'm the strongest on uphill finishes like this," Ricco said.

"On Friday I attacked a bit early and suffered before the finish. This time I followed Andreas Kloden and then when I saw him struggling with about 700 metres to go I went myself and opened a good gap."

Ricco now seeks to defend the overall race lead in Sunday's 20.5km individual time trial.

"Alexandre Vinokourov is my biggest rival because he can time trial very well and looks on form, but I know I have a chance of pulling some time back on Monday's uphill finish to San Giacomo."

World champion Paolo Bettini of Italy was involved in a crash five kms from the end of the stage. The Quick Step rider finished the stage but hurt his left knee and left shoulder after hitting a signpost.

Tour de France contender Ivan Basso of the Discovery Channel team retired after 36 kms of Saturday's stage due to a wrist injury he sustained on Friday.