May 11, 2005 – Contact between Paolo Bettini (Quickstep) and Baden Cooke (FDJ) in the final sprint resulted in a crash and a relegation, pushing Luca Mazzanti (Ita) Ceramica Panaria to the top of the podium in the crash-plagued 211km fourth stage from Giffoni Valle Piana to Frosinone. Bettini, who was relegated to fourth after forcing Cooke into the barrier in the wild finish, was nonetheless able to maintain his pink leader’s jersey: far from mounting a passive defense of his early leadership, Bettini is clearly intent on making up for disappointing early season results with a show of force.

The first serious break of the day saw Cedric Vasseur (Cofidis) and Marco Pinotti (Saunier) break away despite a fast early pace and build an advantage of over five minutes. The high pace led to a series of crashes, involving Nick Gates (Davitamon), Walter Beneteau (Bouygues), Cyrille Monnerais (Francaise Des Jeux), Thomas Dekker (Rabobank), Andrea Peron (CSC), and Nicolas Inaudi (Cofidis), who was brought to hospital and has abandoned. Less than fifteen kilometers from the finish Daniel Schnider (Phonak), Mirco Lorenzetto (Domina), David Zabriskie and Frank Schleck (CSC) and prologue winner Brett Lancaster (Ceramica Panaria) and others crashed as well.

Meanwhile, Bettini was staying where leaders should in a patchy race — at the front. Responding to an attack by Aitor Gonzalez (Euskaltel) near the finish, he made sure to stay well ahead of the carnage behind. A final sprint was led by Mirko Celestino (Domina) though the twisting streets of Frosinone, with Bettini and Cooke in tow. But the final crash of the day would be the most costly: trying to pull around Bettini for the stage win, Cooke was pushed left by Bettini, hit a barrier and went down. Result: a lost sprint for Cooke and relegation for Bettini, who went to fourth due to a 2-second gap between the first four finishers and Celestino in fifth.

Results:
1 Luca Mazzanti (Ita) Ceramica Panaria 5.10.09
2 Dario David Cioni (Ita) Liquigas – Bianchi
3 Michele Scarponi (Ita) Liberty Seguros-Würth Team
4 Paolo Bettini (Ita) Quick.Step
5 Mirko Celestino (Ita) Domina Vacanze 0.02
6 Filippo Pozzato (Ita) Quick.Step 0.04
7 Erik Zabel (Ger) T-Mobile Team
8 Danilo Di Luca (Ita) Liquigas-Bianchi
9 Robbie McEwen (Aus) Davitamon-Lotto
10 Cristian Moreni (Ita) Quick.Step

General classification after stage 4:
1 Paolo Bettini (Ita) Quick.Step
2 Danilo Di Luca (Ita) Liquigas-Bianchi 0.13
3 Luca Mazzanti (Ita) Ceramica Panaria
4 Dario David Cioni (Ita) Liquigas-Bianchi
5 Damiano Cunego (Ita) Lampre-Caffita 0.21