The resignation of President Robert Mugabe, 73, was top of the list of demands of the protesters, angry at the police shooting of a student at an earlier demonstration. Those who chanted "Mugabe Out" also demanded the return of Dzikamayi Mavhaire, a member of the ruling Zanu-PF party recently suspended for daring to utter in parliament the message from the street.
In a debate on constitutional reform of the one-party state, Mr Mavhaire forgot the need for diplomacy, and while arguing that the constitution must be altered to prevent a president serving more than two terms, said: "Mugabe must go." There were gasps in the chamber. It was another landmark in Zimbabwe's slow revolution.
In spite of unprecedented demonstrations, riots and strikes, Mr Mugabe still believes the country which once adored him for seeing off white settlers can be jollied along with a few revolutionary songs and a Mugabe T-shirt. But he cannot ignore the thirst for change. Mr Mavhaire's outburst confirmed that rebellion against him is spreading even in the ranks of his own party.
A growing number of party members privately admit Mr Mugabe is now a liability. Even the parliament, where the dice is loaded to ensure Zanu holds 147 of the 150 seats, has ceased to be behave like a rubber stamp.
"He is besieged from without, and more significantly now from within," says Iden Wetherell, assistant editor of the Zimbabwe Independent, one of the few independent voices in a largely state controlled media. "The most significant feature of recent months has been the deathly silence of Mugabe's senior ministers. They are watching, waiting and rubbing their hands."
Hence Mr Mugabe's delay in announcing a reshuffle of his 56-strong cabinet - the lodestone of the complex, and corrupt system of patronage constructed over Mr Mugabe's 18-year rule. During that time the constitution has been adjusted to concentrate more power in the president's hands.
Mr Mugabe's stranglehold owes something to the Zimbabweans' patience. But in December last year that patience started dissolving as the Zimbabwe Congress of Trade Unions (ZCTU) staged its first ever national strike in protest at the government's economic failures. Riots over rocketing food prices followed.
Responsibility for the crisis is generally laid at Mr Mugabe's door, despite his attempts to blame the country's affluent white minority.
Not everyone is gloomy about the looming upheaval. "People think the country is collapsing," says David Chimhini, director of the human rights organisation ZimRights, "but the disintegration of the ruling party is an advantage in the building of Zimbabwe's nascent civil society". Human rights groups, trade unions, churches and brave individuals like Margaret Dongo, the only true opposition voice in parliament, are dedicated to the development of civic institutions.
While Ms Dongo braves petrol bomb attacks to lay the foundations of a movement which might become an opposition party, ZCTU secretary general Morgan Tsvangirai is now the reluctant leader of mass resistance.
At union headquarters a security guard mans a newly installed iron entrance gate. Blood stains on the carpet in Mr Tsvangirai's office confirm that opposition in Zimbabwe is not for the faint-hearted. After the general strike, Mr Tsvangirai was beaten unconscious and left for dead by veterans of the war against the old white regime.
It was the veterans' demands that the government honour pension promises - after millions of dollars were plundered from the state veterans' fund - which caused the government to raise taxes and precipitated the general strike. Mr Tsvangirai's criticisms of Mr Mugabe's capitulation to their demands brought the ex-combatants to his door: he believes the government was behind the attack.
The fear is that unless the system, as well as the president, changes, a deposed Mugabe might just be replaced by a Zanu clone.