A stunning performance by an upstart anti-corruption party helped topple India's ruling Congress in elections to New Delhi's state assembly Sunday, only months before the country goes to the polls.
Congress, in power at national level for a decade, was also in danger of losing control of three other state assemblies up for grabs in Sunday's vote count, in a devastating blow ahead of next year's general election.
"All I can say is that the people of Delhi have taken a decision which we respect," said Chief Minister Sheila Dikshit as it became clear that Congress would come a distant third in Delhi after 15 years in power.
"We will analyse later what went wrong," added Dikshit, who lost her own seat to Arvind Kejriwal, leader of the fledgling Aam Aadmi Party (Common People's Party).
Kejriwal, who only started his party a year ago, said his was a "victory of the people".
"I am absolutely confident that finally the country will win, the people will win and democracy will win," added the former civil servant, who has tapped into growing anger over corruption during Prime Minister Manmohan Singh's tenure.
Aam Aadmi would even manage to prevent the main Hindu nationalist opposition Bharatiya Janata Party (BJP) from winning a majority in New Delhi, according to forecasts from the electoral commission.
The BJP had either won or was leading in 31 of the Delhi assembly seats while Aam Aadmi was in line to capture 27 seats. Congress trailed in third with a forecast tally of just nine, down from 43.
Official forecasts based on partial results showed the BJP would record landslide wins in the states of Rajasthan and Madhya Pradesh, although it had only a slender lead over Congress in restive Chhattisgarh.
The elections for the four states have been held at different points over the last month but the counting had been postponed until Sunday.
Votes will be counted in the remote Congress-ruled state of Mizoram on Monday.
Aam Aadmi only fielded candidates in New Delhi but the results will increase expectations that it will run nationwide when the world's largest democracy holds its general election, by next May at the latest.
"We have succeeded in altering the political discourse of the elections," Atishi Marlena, one of Kejriwal's top lieutenants, told the NDTV network.
"I think it's historic that a party that was formed just a year ago, a party which was written off till yesterday by the other two big parties, has made such a spectacular debut."
Triumphant Aam Aadmi supporters at party headquarters waved brooms -- the symbol of its pledge to clean up politics.
BJP activists celebrated in Delhi, Madhya Pradesh and Rajasthan, dancing to the beat of drums, bursting firecrackers and waving the party's lotus symbol.
The assembly votes mark the last major test before Congress and the BJP, fielding hardliner Narendra Modi as its candidate for the premiership, face off in the general election.
Rahul Gandhi, who is expected to lead the Congress general election campaign, said the party understood voters' anger and in particular would learn lessons from Aam Aadmi's strong showing.
"It's our duty to listen to you... I want to tell you that we have heard what you have said," said the 43-year-old, whose father, grandmother and great-grandfather have all served as prime minister.
"The Congress party has the ability to transform itself, has the ability to stand up to the expectations of the people of this country. The Congress party is going to do that."
Analyst Amulya Ganguli said the chickens were coming home to roost for Congress after economic growth slowed to around five percent and following a series of corruption scandals -- including surrounding the chaotic 2010 Commonwealth Games in Delhi.
"Had they managed to keep the economy buoyant, then that would have at least been a buffer against the numerous scams during their time," he said.
The elections are also a test for Modi, who is popular with middle-class voters but whose reputation was tarnished by deadly anti-Muslim riots that occurred on his watch as Gujarat chief minister in 2002.
Modi, 63, voiced delight on Twitter, congratulating the party's leaders in Madhya Pradesh and Rajasthan for their "wonderful performance" and "historic victory".