Narendra Modi is the first prime ministerial candidate to stand in the 3,000-year-old city where several religions mingle. Varanasi is an ancient centre of Buddhism but one in six voters is Muslim; Hindus believe that to die here brings salvation by escaping the cycle of reincarnation.
A triumph in the city - one of 41 seats in Uttar Pradesh, Bihar and West Bengal which are voting on the final day of India's five-week general election - would crown a gruelling campaign by the 63-year-old chief minister of Gujarat to lead his Bharatiya Janata Party (BJP) back to power after a decade in opposition.
Campaigning mainly on promises to create jobs and restore India to a path of high economic growth, Modi - whose critics accuse him of harbouring Hindu supremacist views - has largely steered clear of religion.
His oratory skills and high-tech campaign have made him a solid favourite in opinion polls to unseat the Nehru-Gandhi dynasty from New Delhi - and easily take Varanasi.
Modi "will win the election from this Varanasi constituency with a large majority", BJP President Rajnath Singh told reporters as campaigning wrapped up at the weekend. All other candidates would "lose their deposits".
Congress, which has lost popularity after a string of corruption scandals and a sharp economic slowdown, promises to extend welfare policies that helped it sweep into a second term five years ago. "I am confident of giving a tough fight to Narendra Modi," its candidate Ajay Rai told Reuters.
Buoyed by reports from the field in the eight rounds of voting already held, BJP leaders predict that the party and its allies may win a record 300 seats - above the 272 needed to secure an outright majority.
They will get an idea of whether they are right soon after voting ends on Monday, with the first TV exit polls due to be released at 6:30 p.m. (1300 GMT). The official count is due on Friday.
Market rumours that the exit polls would point to a clear BJP victory sent Indian stocks to a record high last week, a sign of investor hopes that Modi would win a clear endorsement for his 'Gujarat model' of pro-business policies.
Polls have got it wrong in the past, however, falsely predicting that the BJP would win in 2004. India's bourse regulator has asked exchanges to test their systems to cope in case there is a sell-off on Tuesday.
If Modi falls short, not only might he miss out on the premiership, but India would also face uncertain talks to form a coalition government that - even if led by the BJP - could fall hostage to the demands of regional parties.
BATTLE OF THE ROADSHOWS
The baking streets of Varanasi have witnessed a procession of carnival-style 'roadshows' where candidates sought to prove their pulling power among locals whose voting patterns are tied to caste as well as religion.
Even Rahul Gandhi, whose lacklustre campaign is likely to end in the worst-ever defeat for the ruling Congress party, drew big crowds on Saturday, in a response to Modi's campaign stop in his own constituency days earlier.
"Congress is a good party which has provided security and employment to Muslims - we trust this party," said Shakeel Ahmed, a 45-year-old Muslim who sported an orange, white and green Congress sun visor and works as a silk weaver.
As Gandhi's bandwagon drew away, one younger man said he would vote for anti-corruption campaigner Arvind Kejriwal, the leader of the Aam Admi, or Common Man, party who has gone head to head with Modi.
"Modi is not a good man," said Faizan Ansari, 19, also a silk weaver. "His people say that those who oppose him should go to Pakistan. We love India. We don't fear Modi."
That antipathy stems from Modi's handling of sectarian riots in Gujarat in 2002, in which more than 1,000 people were killed, most of them Muslims. Modi denies wrongdoing, and a probe ordered by the Supreme Court has found no case for him to answer.
SPLITTING THE VOTE
However, with anti-Modi votes split between Aam Admi and Congress, none of his rivals predict victory in the ancient city, where Hindus bathe daily in the Ganges. One local poll published by the India Today media group gives him 56 percent of the vote in the city, with the Congress candidate a distant second.
"There is no contest in Varanasi," said Koushal Kishor Mishra, a political science professor at the Banaras Hindu University in Varanasi. "The Modi wave is there - I don't know if it is a tsunami or not."
Modi has raised the stakes by attacking regional rivals that he might need to call on if the BJP-led National Democratic Alliance does fall short of a majority, potentially undermining his bid for the premiership.
He spent the last day of a 300,000 km (185,000-mile) campaign odyssey on the road in Uttar Pradesh, also appealing in a blog post for a clean sweep of India's most populous state.
With Modi gone from the city, it fell to lookalike Ranvir Dahiya, a retired bus driver from New Delhi, to show the BJP's colours on the streets of Varanasi. The BJP loyalist, campaigning with a group of about 20 orange-clad party activists, was no less confident than the real Modi.
"Modi will win in Varanasi with a majority of 300,000 to 400,000," said Dahiya, who, like Modi, wore steel-framed glasses and a silver beard.