Greek violence echoes riots of 2008
It was a very Greek riot, complete with an angry, Orthodox cassock-clad priest in among the anarchists.
Impervious to clouds of tear gas and flying chunks of marble, smashed by sledgehammer-wielding youths from the walls of a fountain, the priest went face to face with riot police, telling them to leave the square.
He seemed to be preaching to the converted.
Although 5,000 police were supposedly deployed in Athens to protect the city centre, they surrendered Constitution Square to the anarchists, moving back to form defensive lines around the parliament.
The promises of the Socialist government to never again allow a repeat of the riots of 2008 went up in flames.
After hours of running battles, the black flags of the rioters were flying in victory.
They celebrated their dominance by setting fire to two mobile phone booster trucks.
Firefighters, standing slightly off the battleground, ventured in and doused the flames before they could be completely destroyed.
One of the trucks was looted.
"Stop fighting, get back into the square peacefully," appealed a member of the Indignant movement through a tannoy system from the camp in the centre of Syntagma.
They had been here for four weeks, and their non violent protest had helped force a cabinet reshuffle.
Now they were being tainted by the worst trouble the square had seen since December 2008, during the riots following the murder, by a policeman, of Alexis Grigoropoulos, a 15-year-old schoolboy.
"Batsi, gourounia, dolofoni," chanted the rioters.
The translation means, "Cops, pigs, murderers." It was the battle cry of 2008.
'Shift the agenda'
"Violence... is demoralising for the peaceful demonstrators who couldn't make it to the square," said Fivos Gouzios, a 26-year-old unemployed left-wing political scientist.
He has been involved in most non-violent protest since Alexis Grigoropoulos was shot dead in Exarchia, the "Bohemian" district of Athens.
"The violence helps the government. Violence is never a political proposal," he said.
"The government needs these kinds of incidents in order to shift the agenda from what's happening inside the parliament to what's happening outside.
"Being able to accuse every peaceful demonstrator of being violent. The government has done it before. They're doing it now. It's about time the European Union realises what is happening."
With so many missiles flying through the air, there were some casualties and occasionally the skirmishes ebbed so they could be helped to safety.
These scenes may disturb Greece's international creditors, but people in this city have seen them time and time again and they are not a true representation of most Greeks views.
A close run thing
But as far as Deputy Prime Minister Theodore Pangalos is concerned they are a taste of what would happen to Greece if it left the eurozone and returned to the drachma.
He warned that the country would have to deploy the army if it went back to the drachma to protect banks from people trying to take out their money.
Greece only got rid of its military dictatorship in 1974 and modern historians will understand that the vast majority of people in this country have got no desire to turn the clock back.
The vote in parliament looks like being a close run thing.
But despite the high drama, most political analysts are convinced that Mr Papandreou will win and that Greece will get its next tranche of money from its international creditors.