Italy's Renzi wins regional vote, low turnout sends warning ROME (Reuters) - Italian Prime Minister Matteo Renzi's center-left Democratic Party (PD) won regional elections in Calabria and Emilia Romagna on Sunday but an exceptionally low turnout suggested growing disillusion among many voters. After years of economic crisis that has created hardship among a growing number of Italians, the lackluster turnout was a clear warning sign for Renzi as he faces pressure to push through potentially unpopular financial belt-tightening. Renzi, who scored a record victory in European elections in May, claimed another win but acknowledged that large numbers of voters had stayed away. The turnout was bad, the results were good. A clear 2-0," he said in a tweet on Monday. "Slap in the face from abstentions," read the headline in the Corriere della Sera, Italy's biggest daily newspaper. In the central region of Emilia Romagna, traditionally a stronghold of the left, PD candidate Stefano Bonaccini won 49 percent with the support of the leftist Left Ecology Freedom party. However, turnout was just 40 percent, down from 65 percent at the previous election, with many voters apparently put off following the resignation in July of center-left governor Vasco Errani in a fraud scandal. In the southern region of Calabria, PD candidate Mario Oliverio won more than 61 percent with the support of smaller leftist and centrist parties. Turnout was 44 percent against almost 60 percent last time. In Emilia Romagna, the anti-immigrant, anti-euro Northern League party - which campaigned in a center-right coalition including ex-prime minister Silvio Berlusconi's Forza Italia, did better than expected, winning nearly 20 percent of the vote, while Forza Italia took 8 percent. Matteo Salvini, the 41-year-old who has shaken up the Northern League since the resignation of founder Umberto Bossi in a 2012 finance scandal, said the result was "stupendous" and would help the party break out of its northern base. "It's a result that allows me to go across Italy, from north to south because I want to get to 51 percent of the electorate," he told RAI state radio. The anti-establishment 5 Star Movement led by former comic Beppe Grillo took just 13 percent, underlining the decline it has suffered since its triumph in last year's general election. In Calabria, the center-right coalition led by Forza Italia came second with almost 24 percent, while the 5-Star Movement took under five percent.