By Julien Pretot
BRUSSELS (Reuters) - Alessandro Petacchi used patience and experience to get through a crash-filled first stage of the Tour de France and snatch his first sprint victory on the race for seven years.
The last 2.5 kilometers of the 223.5-km ride to Brussels descended into mayhem with many of the favorites involved in crashes.
"The stage was nervous all day but the end was madness. It was chaos," said prologue winner and yellow jersey holder Fabian Cancellara, who was caught in the final, big pile-up a few hundred meters from the line.
Briton Mark Cavendish, winner of six stages last year, missed the turn leading to the last stretch and crashed out of contention alongside three-times world champion Oscar Freire of Spain.
Cavendish had the consolation of seeing his closest team mate, Mark Renshaw of Australia, take second place behind Petacchi. Third place went to Norway's Thor Hushovd, who beat Cavendish for the points classification green jersey last year.
Cancellara retained the overall lead and escaped from the chaos relatively unscathed like most of the other favorites, including seven-times Tour winner Lance Armstrong and defending champion Alberto Contador.
"I had to brake behind Cancellara and I was stopped by the crash. But everything is fine. Another day out of the way," said Contador, who scraped his left leg in the collision.
"It was total mayhem, especially in the finish but actually all day," American Armstrong said.
"We had a dog running in our group who caused a crash with two of our guys. There were millions and millions of people on the roads. It is a blessing and a curse, it's so great to have so many supporters but it makes the guys super nervous," he added.
The dog incident also involved Briton David Millar, who is third overall, and Giro d'Italia winner Ivan Basso.
"It was a strange finale. The roads were reasonably wide but to win a Tour stage is so huge and the bunch was so motivated and nervous that people take risks," said Millar.
If it is any consolation for the Briton and Basso, a similar incident involving a dog happened in 1973 in a stage between Rotterdam and Brussels and the rider who crashed, Luis Ocana, went on to win the Tour.
The most seriously injured rider on a decidedly bad day for Cavendish was his Australian team mate Adam Hansen, who suffered a suspected broken collarbone.
The day finally belonged to Petacchi, the most successful active rider with 155 wins, who made the right decision by starting his sprint from afar.
"It was seven years since I last won on the Tour so this is beautiful. It really is a different race and the stage was more like a one-day classic, nervous from the start," he said.
The Lampre rider had won four Tour stages in 2003 but had not been back on the race since 2004. His career was halted by a doping suspension in 2008.
Monday's 201-km second stage to Spa could be another jittery ride on the roads of the Liege-Bastogne-Liege classic.
(Editing by Clare Fallon)