Incumbent Prime Minister Narendra Modi's Hindu nationalist party is on track to win the first back-to-back majority in India since 1984.
Hindu nationalist Prime Minister Narendra Modi vowed an "inclusive" future for all Indians on Thursday after a landslide election victory that crushed the Gandhi dynasty's comeback hopes once again.
"Together we grow. Together we prosper. Together we will build a strong and inclusive India. India wins yet again!," Modi tweeted as delirious supporters of his Bharatiya Janata Party (BJP) celebrated nationwide.
"The faith placed in our alliance is humbling and gives us strength to work even harder to fulfil people's aspirations," he said before arriving at BJP headquarters flashing victory signs with both hands and being showered in petals.
Although final results were yet to be published, a rolling vote count by the election commission showed the Bharatiya Janata Party (BJP) increased its majority with 302 out of 543 elected lower house seats.
The BJP's main rivals Congress were on just 51 seats, with Rahul Gandhi - the great-grandson, grandson and son of three premiers - conceding defeat and congratulating Modi.
In an added personal humiliation Gandhi, 48, also admitted he had lost Amethi, a seat long held by his famous family, to a former television star running for the BJP.
The BJP's headquarters in Delhi erupted in celebration with drummers, firecrackers, dancing and singing as hundreds of party faithful thronged the yard and nearby streets waiting for Modi.
"Modi will make India great again. Modi is the strongest prime minister India has ever had and will get. We need to support his policies to prosper," said one supporter, Santosh Joshi.
At Congress headquarters, a handful of dejected supporters sat in groups under the shade of trees.
"We are sad but we will rise again. Modi won because of his lies and false promises. The country is in danger now," Rajesh Tiwari, a Congress supporter, told AFP.
India's main Sensex index breached the 40,000-point level for the first time as the count pointed to a Modi win, following strong gains since Monday.
An international pariah
Monika Barthwal Dhatta, from UNSW, said that when Modi came to power in 2014 his image at the global level "was that of an international pariah".
"Things shifted quickly," she said. "Modi truly embraced his role as India's leader and showed an unprecedented level of energy, assertiveness and enthusiasm in terms of dealing with other powerful states, like the US, and China.
"This has gone down particularly well, not just among his supporters, but more widely among young Indians.
"It's remarkable the extent to which national security issues became enmeshed within the domestic political debate leading up to the elections, and that went well with Modi's base, and so there's nothing to say we won't see more of that in coming years.
"There's certainly the sentiment among many commentators that we have seen a level of assertiveness from Modi in dealing with major powers like China, like the US, that we have not seen before. Given that, the challenges around dealing with a rising China, while developing stronger strategic relations with the US, there is certainly a sentiment that Modi is the person to lead India through these challenges.
"Because of what happened in February, the BJP and Modi were able to use discourses around national security and Pakistan as a military threat in ways that it would not have been able to, had those events not taken place."
The vast size of India - stretching from the Himalayas to the tropics, taking in polluted megacities, deserts and jungles - made the world's biggest election a marathon six-week endeavour.
The campaign, estimated to have cost more than $7 billion, was awash with insults - Modi was likened to Hitler and a "gutter insect" - as well as fake news in Facebook and WhatsApp's biggest markets.
Gandhi tried several lines of attack against Modi, in particular over a French defence deal and high unemployment and saying Modi was dividing the officially secular country.
Lynchings of Muslims and low-caste Dalits for eating beef and slaughtering and trading in cattle have risen, with critics saying extremists have been emboldened by the BJP coming to power.
Modi's pledge of a strong stand against a separatist movement in Muslim-majority Kashmir has fuelled tension with nuclear-armed rival Pakistan, although its prime minister, Imran Khan, congratulated Modi on his win.
"Look forward to working with him for peace, progress and prosperity in South Asia," Khan added on Twitter.
Several cities with names rooted in India's Islamic Mughal past have been renamed, while some school textbooks have been changed to include references to Hindu right-wing ideology, culture and history.
I congratulate Prime Minister Modi on the electoral victory of BJP and allies. Look forward to working with him for peace, progress and prosperity in South Asia— Imran Khan (@ImranKhanPTI) May 23, 2019
The NDA's predicted margin of victory, at 351 seats versus 93 for the Congress-led United Progressive Alliance, according to broadcaster NDTV, far exceeds survey forecasts in the run-up to the vote.
Among the winners for the BJP was a Hindu ascetic accused of plotting a bomb attack on Muslims.
More fragmented parties
Pradeep Taneja, from the University of Melbourne, said This time, the political parties, the opposition, in particular, was much more fragmented than in the past.
"There really wasn't a major national opposition party. Congress is the main opposition but they are weakened," Mr Taneja said.
"Fifteen, 20 years ago, Congress was the only national party. The BJP was not as strong, but the tables have really turned. The BJP has now become the strongest national party.
"There will be a continuity of policy, and many of the programs started by Prime Minister Modi, for example, clean India, digital India, make in India, it should all get a further impetus.
"In the past five years, one of the fundamental changes that India has witnessed is the role of religion in politics. Previous governments have kept religion out of politics. Prime Minister Modi has changed all that.
"Certainly a stronger economy will make India a much stronger international player, and therefore the focus on this government is hopefully going to be on strengthening the Indian economy."
But Modi, 68, managed to deftly turn the election into a referendum on his rule while depicting himself, often in the third person, as the only one able to defend India.
In this, he was given a major boost when a suicide bombing, claimed by a Pakistan-based militant group, killed 40 Indian paratroopers in Indian-administered Kashmir on 14 February.
Doubts abound about the efficacy of India's subsequent air strikes on Pakistan, but the action enabled Modi to style himself the "chowkidar" ("watchman").
"We have shown the world that India is a great country. We have shown Pakistan that they cannot mess with us," said Vishal Sharma, a BJP supporter in Delhi.
"Congress sold the country for all these decades. Now is the time to rebuild the nation."
Congratulations to Prime Minister @NarendraModi and his BJP party on their BIG election victory! Great things are in store for the US-India partnership with the return of PM Modi at the helm. I look forward to continuing our important work together!— Donald J. Trump (@realDonaldTrump) May 23, 2019
Pakistan Prime Minister Imran Khan on Thursday congratulated Modi and said he looked forward to working for "peace, progress and prosperity in South Asia".
His message came just hours after Pakistan's military said it tested a surface-to-surface ballistic missile capable of carrying conventional and nuclear warheads - a day after an Indian missile test.
But while Pakistanis consider Modi a hardliner, analysts say his victory could improve relations between the arch foes.
"The expectation in Pakistan is that there will be an incremental improvement in Pakistan-India relations as Modi's attitude would be more relaxed," retired Pakistani general Talat Masood told AFP.