With dozens of new lawmakers from an Italian protest movement still dazed after a shock election success, the party's former comedian turned activist leader was suddenly in the driving seat on Tuesday.
Beppe Grillo's Five Star Movement (M5S) captured over a quarter of the vote for the lower house, incredibly becoming the biggest individual party in parliament and the number three grouping after the main right and left coalitions.
"Grillo will play a decisive role. He has to decide whether to strike a limited agreement with the left or whether to go for fresh elections," said Roberto D'Alimonte, a politics professor at Rome's LUISS university.
"All the cards are in his hands," D'Alimonte said.
It is a stunning turn of events for the tousle-haired 64-year-old who has spoken to packed squares across the country during the campaign, channelling the discontent of Italians fed up with austerity and corrupt politicians.
Grillo set up his group in 2009, initially as one of several citizen movements against then prime minister Silvio Berlusconi.
It was dismissed as a sideshow in Italian politics but it quickly captured youth support with its irreverent and Internet-based campaigning.
As scandals have mounted in recent months in Italy over the massive waste of public funds by politicians showered with perks and cash handouts, the M5S has gained in popularity and become a political force.
The first display of its new power came last year when it won the highest number of votes for any single party in regional elections in Sicily.
In the Sicilian regional government, M5S lawmakers won praise for slashing their own salaries and putting the money into a fund to help small businesses.
They also successfully lobbied against the installation of a US radar system in a nature reserve -- an example of the type of local issue that is often most crucial for the "Grillini" as Grillo's followers are known.
The party's platform has been generated through online contributions and the campaign has been run on a shoe string budget.
Many of the new lawmakers are very young -- some are close to the minimum age of 25 for entering the lower house -- and they espouse an eclectic mix of environmental and leftist causes as well as a general anti-sleaze ethos.
Virtually all the candidates were newcomers to politics including students, housewives, doctors, laid-off factory workers and even an astrophysicist.
Supporters say Grillo's movement has breathed new life into politics but critics warn it is an unpredictable populist group with completely unrealistic aims -- like the cancellation of Italy's debt and a 20-hour working week.
The movement "has no spokesman or clear mechanism for deciding on policy," said James Walston, a professor at the American University of Rome.
"It might dissolve in a few weeks, it might develop an independent statute or it might stay under Grillo's direct control," he said.
Editorialist Stefano Folli said the possibility of a centre-left government without a fixed majority supported by Grillo in parliament on a bill-by-bill basis would be "very weak".
"It would hand the government to Grillo," Folli, who writes for Il Sole 24 Ore business daily, told AFP.
An added complication is that Grillo himself will not enter parliament as he has a conviction for manslaughter over a car accident in the 1980s in which three people died -- excluding him under his movement's own rules.
The prospect of an unelected anti-system activist pulling the strings in Italian politics from outside parliament has seasoned observers worried.
"One in four Italians voted for a party that says no to almost everything," said Franco Debenedetti, also a columnist for Il Sole 24 Ore.
Others have been more positive however, with La Stampa editor Mario Calabresi saying the party "should be treated as a resource, not as enemies.
"They are representatives of Italians, like everyone else," he said.
In an interview on election night on Monday, Grillo said his movement's success sounded a death knell for the mainstream political parties and predicted they would only last "another seven or eight months".
"They've failed, both left and right. They've been there for 25 years and they've led the country into this catastrophe. Italy's problem is these people. They won't last long. Not long at all."