The flotilla of motorboats carrying family, officials and ashes had arrived early at the pontoon, moored mid-river. The truck carrying them through the city to Sarawati Ghat had moved swiftly past thin crowds lining the route of their procession. At centre stage was Gandhi's great grandson, Tushar Arun Gandhi, who had fought a two-year legal battle for possession of the ashes, which had been misplaced in a bank vault in the eastern state of Orissa 47 years earlier.
Instructed by a Hindu priest amid the chanting of Vedic mantras, Tushar Gandhi had poured so much milk and water into the urn that those watching expected its contents to be almost entirely liquid.
Initially they were, then came a great dusty cascade, pouring forth and billowing up from the surface of the water, enveloping the chosen few invited to witness the "historic" spectacle.
It was the farcical end to a saga which had never seemed quite real.
From the beginning, doubts about the authenticity of the ashes, and Tushar Gandhi's motives, persisted.
"If these are truly Gandhiji's last remains, why has the Prime Minister not come? Where is the President of India?" asked Sunit Dyas, 66, who described himself as a "freedom fighter" and who blamed bungling by the authorities for the small turnout.
In February 1948, several million people attended similar ceremonies across India when Gandhi's ashes were dispersed after his assassination by a Hindu extremist and cremation at Raj Gat in Delhi.
Officials at the State Bank of India's Cuttack branch, where one of the urns was deposited in 1950 and forgotten, swear the ashes are genuine, and Tushar Gandhi responds with contempt to suggestions that he has used his famous relative's remains to build himself a political profile.
"They [the critics] can wait and watch," he told The Independent on arrival in Allahabad after a 19-hour train journey accompanying the ashes from Orissa.
"I have not sunk so low that I would use an occasion like this for personal gratification or enhancement ... in our religion this is supposed to be a very sacred duty to perform, and getting a chance to do this almost 50 years after his [the Mahatma's] death is a miracle."
Speaking from New Delhi, Rajmohan Gandhi, a grandson of the Mahatma, supported Tushar Gandhi's actions.
"He read in a newspaper that the ashes had been found, and thought something should be done," he said. "A fairly natural reaction I would have thought."
The fact that Mahatma Gandhi was a married man, whose wife Kasturba gave him four sons, is news to many in the West, brought up to believe India's most famous independence campaigner was a total ascetic. Another common misconception is that former Indian Prime Ministers Indira and Rajiv Gandhi - assassinated in 1984 and 1991 respectively - were his descendants. They were not related.
If Tushar Gandhi is trying to use his great grandfather's reputation to build popular support he may find it an uphill battle.
While Gandhian ideals may have inspired such figures as Martin Luther King Jnr and Nelson Mandela, here they are associated with the Congress Party, which last year recorded its lowest ever vote in a national election.
"[Gandhi] is the presiding deity of a system that negates every conviction he stood for," wrote Vandita Mishra in the English-language daily The Pioneer. "He keeps alive for us a faith we have ourselves long [since] surrendered."
The Congress Party, which was founded in this city more than a century ago, managed to organise a rowdy mob to welcome Tushar Gandhi to Allahabad Junction railway station, largely for the benefit of the television cameras.
But though the Mahatma's lofty ideals of self-sacrifice and non-violence may have less currency in an increasingly materialist India, his methods remain popular.
This week's events coincided with a fast-unto-death by an academic at Allahabad University, Dr Ram Shastri, in protest against violence by students.
Fasting was one of Gandhi's favourite methods for achieving harmony between Hindus and Muslims, and equality for Untouchables and low caste Hindus.
The immersion of the ashes closes the circle on Gandhi's long association with this city of 1 million people, once known as the "Oxford of the East" for its manicured gardens and famous university, but which now lacks even a domestic airline service.
Yet certainty that Mahatma Gandhi can truly rest in peace depends on whether there are other hidden relics tucked away in corners of India.