Italy's main opposition party, the populist Five Star Movement (M5S), was early on Monday recognized as the landslide winner of mayoral elections in Rome, leaving Prime Minister Matteo Renzi and his Democratic Party (PD) licking their wounds.
Nearly 9 million Italians were eligible to vote in Sunday run-off mayoral contests in more than 100 cities after inconclusive first ballots held two weeks ago. Several big cities were involved, but the most important race was in Rome.
According to Interior Ministry data covering more than 99.8 per cent of polling stations in the capital, M5S candidate Virginia Raggi won 67.2 per cent of the votes, against 32.8 per cent for her PD rival Roberto Giachetti.
In a brief acceptance speech at campaign headquarters, Raggi hailed her victory as a "fundamental, historic moment" for Rome, as it marked the election of the Eternal City's first-ever female mayor. She is also the youngest in more than 100 years.
"With us, a new era is opening," the 37-year-old lawyer said, pledging to restore "legality and transparency" in a city rattled by corruption scandals, urging defeated rivals to be constructive in opposition and declaring herself to be "ready to govern."
Giachetti conceded earlier before his own supporters. "I am responsible for this defeat," the loser said. "It is clear that [Rome will] have a mayor from the Five Star Movement called Virginia Raggi," he added.
Raggi's victory had long been anticipated. She presented herself as a clean broom in a city with broken public services and crippling debt, and where politicians and city officials are on trial for rigging public contracts for the benefit of the local mob.
The most surprising result of Italy's election night was the success of another 30-something female M5S candidate, Chiara Appendino, in Turin. It was another major blow for Renzi's party, whose candidate, Piero Fassino, a former minister, was hoping for a second term.
The governing party avoided a complete rout by winning in Milan with Giuseppe Sala and by retaining control of Bologna, a centre-left stronghold. In Naples, incumbent independent mayor Luigi de Magistris was re-elected, in line with expectations.
"The run-off votes have resulted in clear-cut defeats, with no mitigating factors, for PD candidates in Turin and Rome against M5S candidates, and loud and clear victories in Milan and Bologna against right-wing candidates," Renzi's party said in a statement.
The elections were an important mid-term test for Renzi, even though the premier had insisted that they were only representative of local issues. His government is struggling to revive a flagging economy and dealing with banking and migration crises.
The negative outcome is possibly the biggest setback in Renzi's political career and comes ahead of a crucial vote in October on a wide-ranging constitutional reform. Renzi has staked his career on a victory in the referendum, pledging to otherwise quit politics.