Here are the top 10 developments in this big story:
"We accept the people's mandate with humility. I thank the people of Chhattisgarh, Madhya Pradesh and Rajasthan for giving us the opportunity to serve these states. The BJP Governments in these states worked tirelessly for the welfare of the people," tweeted Prime Minister Narendra Modi, who will be seeking a second term next year.
Shortly before midnight, senior Congress leader in Madhya Pradesh, Jyotiraditya Scindia, tweeted a letter from party chief Kamal Nath to Governor Anandiben Patel, seeking permission to form government. The Governor said an appointment will be given only after the situation is made clear by the Election Commission, reported news agency ANI. Both the Congress and the BJP are expected to meet the Governor on Wednesday.
Madhya Pradesh, where Shivraj Singh Chouhan is seeking a fourth term, is the biggest prize in these polls. The target is 116 in the 230-member assembly. As the results see-sawed, the Congress dialled Mayawati for a Plan B. A leader of Mayawati's party has assured that the party would do all it can to stop the BJP from coming to power.
In Rajasthan, the Congress and its ally Ajit Singh touched the majority mark of 100 seats -- elections were held for 199 of the 200-seat assembly. The BJP has won 73 seats, Mayawati's party has won six. As the gap with the BJP narrowed, Congress's Sachin Pilot said he would like to reach out to "other like-minded parties and leaders to form the government".
The Congress triumph came as Rahul Gandhi completed a year at the helm of the party. The outcome of the elections is expected to boost his leadership quotient and help the Congress get a key position in the opposition's grand alliance for next year. Jubilant with the results, Mr Gandhi said, "Mr Modi has taught me what not to do... Arrogance is fatal for a politician".
The shock defeat for the BJP was in Chhattisgarh, where Raman Singh was considered one of its most popular chief ministers. The Congress has far outstripped the BJP in the Maoist-hit state, winning 65 of the 90 seats and leading in three. The BJP has won 15 seats. The alliance of Ajit Jogi and Mayawati has won seven seats.
K Chandrashekar Rao struck gold in Telangana, winning 88 of the state's 119 seats. Congratulating him, rival Chandrababu Naidu said,"TDP respects the mandate of the people". The Congress-TDP alliance won 21 seats.
In Mizoram, the Mizo National Front won in 26 of the state's 40 seats. The Congress won just five seats. The MNF's victory, for now, also dashed the BJP's hopes to rule the whole of northeast. The party has won only one seat.
While stepping down, Chhattisgarh Chief Minister Raman Singh said the state election, fought on local issues, has no bearing on the national elections. "The 2019 fight will be about who is up against PM Modi," he said.
In Rajasthan, the Congress is yet to face the question of the top job -- the front-runners are Sachin Pilot and two-time chief minister Ashok Gehlot. In case of a victory, a similar task awaits it in Madhya Pradesh, where its three top leaders, Kamal Nath, Digvijaya Singh and Jyotiraditya Scindia, have kept a truce throughout the campaign.