Freire was world champion in 1999, 2001 and 2004
Spain's Oscar Freire surprised the favourites to win the Milan-San Remo classic for the third time on Saturday.
Freire, 34, who triumphed in 2004 and 2007, surged ahead in the final stretch to outsprint Belgian Tom Boonen.
Britain's Mark Cavendish, who won the event in 2009, was dropped 23km from the finish having already had to change a wheel because of a puncture.
"There is a new generation of cyclists coming of age but old riders like me are still competitive," said Freire.
"I've won four out of the five sprints I've contested this year."
The contest ended for an out-of-sorts Cavendish, whose season start was delayed by dental problems, on the penultimate climb.
"I had the spokes ripped out of my front wheel and had to chase to get back on," he told The Guardian.
"I got back on and then there was a crash. I chased again, got on again but on the descent of the Manie I crashed. So I went from the front to the back and had to chase again."
Italian Alessandro Petacchi finished third in the first big classic race of the season.