The second stage was a 156km stage from Jesolo to Trieste and saw the Italian, who was suspended last year by the Court of Arbitration for Sport 'for testing non-negative to asthma medication Salbutamol' and subsequently fired by his then team Milram despite Petacchi being given clearance to use the medication, pull away down the boulevard to the finish with Cavendish today unable to catch him.
The victory in a time of 3.43.07, was Petacchi's 164th stage win and his 24th in the Giro.
Britain Ben Swift was third with Bradley Wiggins 44th, Jeremy Hunt 55th, Daniel Lloyd 69th, Ian Stannard 85th, Chris Froome 91st, David Millar who was over a minute back in 136th place and Charles Wegelius 159th.
Mark Cavendish leads the General Classification by fourteen seconds from Australian Mark Renshaw.