Romans on Monday voted to return the Italian capital to the centre-left after right-wing mayor Gianni Alemanno lost his re-election bid to little known challenger Ignazio Marino in polls marred by low turnout.
Alemanno conceded defeat, saying the results in city races across the country for his People of Freedom party (PDL) led by former prime minister Silvio Berlusconi were "not positive", blaming the losses on Italians' "disaffection" with politics, as only about half of eligible voters cast ballots.
Marino, the candidate of the Democratic Party (PD), was romping to victory with 63.9 percent of the vote, according to interior ministry results published with nearly one-third of the ballots counted.
Rome's former mayor Walter Veltroni said Marino's win was "excellent news for the city".
"The Romans' vote finally ends five years of indifference and the mistakes that Alemanno and his team committed through incompetence, lack of love (for the city) and personal interests," he said.
The Italian left controlled the Eternal City for nearly 20 years, from 1989 to 2008, when Alemanno, a former neo-fascist, was elected mayor on a strong anti-crime platform.
Results seemed to show a clear advantage for PD candidates in most of the some 60 cities and towns where run-off votes were held Sunday and Monday.
Among those changing hands are central Siena and two northern cities, Brescia and Treviso, which had been held by the anti-immigrant Northern League.
Victory for Marino offers a shot in the arm for the PD, which lost ground in this year's inconclusive general elections, and new misery for the PDL, which also fared poorly in previous recent municipal votes.
The two parties formed an unwieldly coalition government in April after weeks of uncertainty following February's elections.
Turnout in the Rome polls was a low 52.5 percent, compared with 67.5 percent in the first round two weeks ago, which itself was 15 percentage points lower than in 2008 municipal polls, according to an initial interior ministry estimate.
The sharp drop was seen as reflecting voters' disaffection with politics after the impasse resulting from February's polls.
"It's not a drop, it's a collapse (in voter participation)," the leading Corriere della Sera daily said in an editorial. "This is disenchantment."
Sociologist Piergiorgio Corbetta, writing in the Rome daily Le Messagero, sees the low turnout as an "alarm signal (that) politicians continue to ignore."
But analyst Antonio Noto of the IPR Marketing polling institute blamed the low turnout on the economic crisis.
"The numbers show that local administrators including mayors are losing sway because of the crisis. Lacking financial means, they cannot carry out repairs or improve services," he told the left-leaning daily La Repubblica.
The Five Star Movement of populist firebrand Beppe Grillo meanwhile suffered a rout in the city polls after riding a wave of discontent with politics as usual to win more than 25 percent of the vote in the February general elections.
None of its candidates scored better than third place in the first-round vote in 563 towns and cities, so they were absent from the run-offs.
Analysts say Grillo's relentless attacks on Italy's governance have destabilised the movement. Last week the former comedian described parliament as a "smelly tomb, good for nothing".