Honda was leading-out Petacchi, winner of Thursday’s stage, when a massive pile-up took out many of the field’s top sprinters in the final 150 meters of the stage.
Hondo continued the charge to the line, edging out Giovanni Visconti (ISD) and Sacha Modolo (Colnago) for the win.
Despite the crash, Petacchi said that he will continue to race.
“I bruised right hip at left elbow, and I have a lot of road rash on my back, but it seems there is nothing serious,” said Petacchi.
Liquigas’s Roman Kreuziger, winner of stage 2 on Wednesday, continues to lead the overall standings with a four-second advantage over RadioShack’s Chris Horner.
The race ends Saturday with a relatively flat 140km stage from Sant’Antioco to Cagliari.