Italy's populist 5-Star Movement (M5S) unveiled its candidate for prime minister Saturday as it braces to attempt a revolutionary shift from protest to ruling party.
Political darling Luigi di Maio, 31, considered the reassuring face of Italy's anti-establishment insurgency, pocketed 30,936 of the 37,442 ballots cast.
"I'll start work tomorrow on putting together a team for government... one the people will be proud of," he said in an emotional speech in the sea-side town of Rimini as his victory was announced.
"It's a huge responsibility, but together we can do it," he added.
The clean-shaven lawmaker had been openly groomed to run for the top job in the spring 2018 general election as an everyman able to win over average voters and financial markets alike.
"Di Maio is studying how to become prime minister; he behaves, speaks, walks like one. He scrutinises the rules of the game to try and beat the house," Luiss University communications expert Alberto Castelvecchi told AFP.
The telegenic youngster had gone up against six totally unknown candidates and a low-profile senator in an electronic vote on Thursday that had both amused and irked traditional parties and the country's mainstream media.
"The pathetic primary with Di Maio as a lone candidate (...) is not only a symptom of a lack of democracy" within M5S, wrote Il Fatto Quotidiano daily, which is usually the most sympathetic to the movement.
"It is also proof of the eternal immaturity, incompetence, inexperience and thrown-together nature of a movement that is getting bigger but not growing up," the paper said.
Italy's media were also quick to point out the movement had hoped more than its over 140,000 members would vote.
- 'Turning point' -
M5S, which bases much of its appeal on fighting corruption, emerged as a major force in 2013 general elections and went on to win mayoral seats in Rome and Turin last year.
And despite a worse-than-expected performance at local elections in June, for months now it has been neck-and-neck in the polls with the centre-left ruling Democratic Party (PD), with recent projections showing it would win 28 percent in a national race.
M5S supporter Roberto Pavanello told AFP he had voted for Di Maio and hoped he would provide "the turning point that Italy needs".
Critics say that regardless of who is candidate for prime minister, 5-Star's outspoken founder, comic Beppe Grillo, will continue to determine how the party is run, crushing any dissent.
Grillo has promised to remain the "guarantor" of the movement's model of direct democracy.
Members were told whoever got the PM candidacy and party leadership would be a mere spokesman, obliged to follow a political programme "for Italy, written by Italians".
The movement has always defined itself as on neither the political left nor right, though it was driven at the start by largely leftist ideals such as calls for a minimum wage, according to political watcher Vincenzo Latronico.
Its leaders have moved sharply across the spectrum since, often echoing the anti-immigration Northern League party.
The movement may have picked its PM candidate, but it will still have an uphill struggle to reach high office.
It categorically refuses to form alliances with any other parties and under Italy's proportional electoral system would need to pocket 50 percent of the vote plus one ballot to obtain a majority in the upper house of parliament.
It would only need 40 percent of the vote in the lower house -- but analysts say that looks like a tall order.