Much of New Delhi's leafy British colonial-era center - the administrative heart of India, home to the presidential palace, Parliament and myriad government ministries - was being sealed off to traffic and pedestrians by about 15,000 police ahead of the run.
The hundreds of thousands of people who work in the area were being advised to keep a low profile, and to keep off the roofs and stay away from the windows of their office buildings.
Authorities desperate to avoid the chaos that has plagued the torch runs in London, Paris and other Western cities had reason to be worried - even the flame's late-night arrival at New Delhi's airport was marred by small protests.
Some two dozen Tibetan exiles chanted anti-China slogans and protested along a busy highway as the torch made its way into the city after being greeted at the airport by flag-waving traditional Indian dancers and Chinese cheerleaders. Several of the protesters were detained by police.
In Mumbai, India's financial capital, police detained about 25 Tibetans who attempted to breach the barricades around the Chinese Consulate. Protesters shouted "Free Tibet" as they were dragged into police vehicles.
Tibetan exiles, who number more than 100,000 in India, have staged near-daily protests in New Delhi since demonstrations first broke out in Tibet in March and were put down by Chinese authorities.
In recent weeks, they have stormed the Chinese Embassy, which is now surrounded by barricades and barbed wire, gone on hunger strikes, and shaved their heads to protest China's crackdown on the Tibet protests.
The exiles say the torch run through the city is a perfect opportunity to make their point, despite the fact that the Dalai Lama, the exiled Tibetan Buddhist spiritual leader, says he supports China's hosting of the Olympics.
"By speaking out when the Chinese government brings the Olympic torch to India, you will send a strong message to Tibetans, to the Chinese government, and to the world, that Indians support the Dalai Lama and the Tibetan people's nonviolent struggle for freedom and justice," said the Students for a Free Tibet, a strident exile group.
Protests were expected to continue all day before the 4 p.m. (1030 GMT) start of the relay.
Thousands of Tibetans were also taking part in their own torch run to highlight the Tibetan struggle against China.
The alternate run began Thursday morning with a Buddhist, Hindu and Sikh prayer session at the site where Indian pacifist Mohandas Gandhi was cremated. The torch was then lighted and Tibetans put on a show of traditional dancing.
Several dozen prominent Indians, including former Defense Minster George Fernandez, joined the Tibetans, who planned to march around the city with their alternate torch.
Some exiles said they planned to make a more dramatic statement later in the day, possibly trying to douse or steal the Olympic flame, although activists were sketchy about their plans.
Tenzin Tsundue, a Tibetan activist with a reputation for publicity stunts, said he didn't want to talk about specific plans in a telephone interview Wednesday because he fears his phone is tapped.
"But be at India Gate," he said, referring to a monument in New Delhi that the torch was to pass.
Activists disrupted torch relays in Paris, London and San Francisco. However, stops in Kazakhstan, Russia, Argentina, Tanzania, Oman and Pakistan were trouble-free.
But in India, public sympathy lies with the Tibetans, who have sought refuge in the country since the Dalai Lama fled Tibet after a failed uprising against Beijing in 1959, setting up his government-in-exile in the northern town of Dharmsala.