Thousands of people were gearing up in the summer heat to celebrate a torch relay around the city, due to start later in the day and involving several leading athletes and celebrities.
The flame, which landed in a special lantern after its private jet Zeus, will be transferred to a skittle-shaped torch under the majestic 13th century Qutab Minar, a 73-metre (239 feet) tall sandstone tower, before commencing the 33.2-km (21-mile) run.
Over 100 runners will carry the torch in New Delhi, which was also part of the global torch relay for the 1964 Tokyo Games.
Former men's 400 metres runner Milkha Singh, India's most revered athlete, and woman shooter Anjali Vedpathak Bhagwat will run the final legs before the show culminates with a grand cultural show at the national stadium, venue of the inaugural Asian Games in 1951.
The thaw in political tension between India and Pakistan will also be reflected in the relay with a team of Olympic officials from Pakistan set to attend the celebrations.
But the relay has triggered some controversy with P.T.Usha, Asian track queen of the 1980s, boycotting the run after being invited only after a media outcry.
"This can happen only in India," she said. "I feel very bad. It's not an opportunity you get every day."
Milkha backed Usha: "Torch-bearers should only be those who have sweated it out for the country. Usha has brought (a good) name for the country."
The flame will travel next to Cairo for its African leg.
It will return to Greece on July 9 for a final homecoming tour before entering the Olympic stadium at Athens to light the cauldron on August 13.