A billion Indians launched the world's biggest party on Saturday, as their adored national team lifted the cricket World Cup, triggering celebrations and firework displays across the country.

From the megacities of Mumbai, Kolkata and New Delhi to India's rural heartland, where entire villages had gathered around television sets to watch the final, this cricket-obsessed nation went into delirious meltdown.

"The whole of India is not going to sleep tonight," said Sania Singhvi, an 18-year-old college student from Mumbai, where the Wankhede Stadium, the match venue, was engulfed in a sea of dancing, cheering Indian fans.

Motorbikes with pillion passengers waving the saffron, white and green Indian Tricolour roared up and down Mumbai's sweeping Marine Drive promenade, weaving in and out of the traffic, as cars hooted their horns in accompaniment.

In the streets of the country's financial capital, people danced and banged drums, cheered on by entire families who had come out onto their balconies and rooftops to watch the party unfold, chanting ‘India, India, India!’

Jaywant Nikam, a 50-year-old architect who was among the 32,000 spectators inside the sold-out stadium who watched India down their South Asian rivals Sri Lanka, was almost overcome by the occasion.

"I was 23 years old when India won the World Cup the first time, and it's so good after so many years to see them win again with my children," a tearful Nikam said, hugging his son and daughter.

His 11-year-old son Vedant was dressed head-to-toe in the Indian team kit, the price tag still dangling from his cap and his face painted in the colours of the national flag.

There were tears of another kind in the Sri Lankan capital, as some fans wept with disappointment after watching their team fall at the final hurdle.

Colombo's Galle Face promenade, where tens of thousands had gathered in expectation of a victory party, took on the atmosphere of a wake, as fans made their way home in silence, shaking their heads and offering each other consoling pats on the back.

Some still managed to put a brave face on their disappointment.

"We must be happy that the World Cup was lifted by a fellow South Asian nation," said Palitha Perera. "We have only another four years to wait."

The victory was especially sweet for the people of Mumbai.

The World Cup final was the city's highest-profile sporting event since the 2008 attacks, which saw 10 Islamist militants kill 166 people at landmark targets, including the Taj Mahal Palace hotel where the teams were staying.

"We are very, very proud of our team," said college student Beenish Shaikh.

"It is truly something to win the trophy after 28 years. We are so happy. We are going to party all through the night."

In Kolkata, thousands of ecstatic fans thronged the city's three kilometre-long (two-mile-long) Park Street boulevard, singing and hugging.

"Many of us were not born in 1983 when India last won the cup," said Neha Keshri, 18.

"We waited through the years, and six editions of World Cups passed by. The moment has come now," she laughed.

Some 3,500 police personnel had been deployed to ensure the safety of the two teams and the spectators in Mumbai, who included both countries' presidents.

Khaki-clad police equipped with bamboo sticks were joined by paramilitaries with full body armour and automatic weapons, as coastguard and navy patrols kept watch on the Arabian Sea and a no-fly zone was imposed over south Mumbai.

Indians from cycle-rickshaw drivers and Bollywood film stars to the prime minister had been swept up in the anticipation, with an Indian swimwear model now stuck with fulfilling her pledge to strip naked for the team if they won.

Cycle-rickshaw driver Sheru Khan, 35, showed his dedication by riding nearly 1,500 kilometres (930 miles) from his home in northern Uttar Pradesh state to Mumbai after being promised a free ticket by a local politician.

Black market tickets for the match had exchanged hands for as much as to $3,300 each, and cricket's governing body was criticised for only making 4,000 tickets available to the general public.

The ‘Mumbai Mirror’ tabloid said that customs officers at the city's airport even offered to waive import duty on a replica of the World Cup trophy in return for seats at the final.