The Italian city of Parma has elected as its mayor a candidate representing a rabble-rousing comedian, in the latest example of Europe's loss of faith in incumbent and mainstream politicians.

Federico Pizzarotti, a 39-year-old IT manager standing for Beppe Grillo's Five Star Movement, trounced a candidate from the centre-left Democratic party, taking 60% of the vote in a head-to-head runoff.

Grillo candidates also won three other mayoral contests in smaller towns across Italy.

Pizzarotti takes over Parma from a mayor backed by Silvio Berlusconi's Freedom People party who stepped down in September after a scandal over town hall finances.

"This is the politics of normal people," said Pizzarotti as he celebrated.

Two weeks ago, after Grillo's candidates took 200,000 votes in the first round of polling, the comic claimed Italians were "voting for themselves". He added that Italy's traditional political parties were now "liquefying in political diarrhoea".

Grillo, 63, has relied on the internet to build his Five Star Movement, campaigning for green issues and against political corruption through his hugely popular blog. In 2007, he staged a hugely successful day of protest (slogan: Go Fuck Yourself) against Italy's politicians, and delivered a 350,000-signature petition to parliament demanding the ousting of MPs with criminal records.

In Parma, popular protest against the mayor, Pietro Vignali, helped force him out of office after he racked up a reported €600m (£485m) in debt. In the first round in Parma, Berlusconi's party won a meagre 4.7%, in one of many dire performances in the hundreds of contests held up and down the country.

Grillo's message has struck a chord nationally this year as Italy's parties battle new funding scandals after being sidelined by the arrival of Mario Monti's government of technocrats, brought in last November to steer Italy through the economic crisis after the resignation of Berlusconi, whom Grillo has nicknamed "the saliva salesman".

The comedian has shown little more patience with Monti, whom he calls Rigor Montis, condemning his austerity-linked tax rises and arguing that Italy would be better off out of the euro rather than trying to save it.

On Monday, a former Berlusconi minister, Mariastella Gelmini, said Grillo's popular appeal reminded her of Berlusconi, who also pitched himself as an outsider when he entered politics in 1994.

Grillo's sometimes outlandish views – he has called for a social wage for all citizens to prevent them commiting suicide – contrast with the sober approach to local politics of his municipal candidates.

"Beppe Grillo brings 12,000 people into piazzas. No other leader is capable of doing that. He is our megaphone," said Pizzarotti. "He digs up the earth like a plough and we follow behind, sowing seeds to grow fruit for our cities."

• This article was amended on 22 May 2012. The original referred to the Five Start Movement.