The party started on a winning note with the first result being declared in Haryana going to its kitty.
Veteran BJP leader Anil Vij won from the Ambala Cantt seat by a convincing margin of 15,462 votes.
"We will form the next government in Haryana. We will get two-thirds majority," BJP leader Abhimanyu said in Hisar.
The ruling Congress, staring at a rout, drew solace with the result of the Jhajjar (reserved) seat going in its favour. Education minister and Congress candidate Geeta Bhukkal won the seat with a margin of 26,854 votes.
If the BJP wins a clear majority in the assembly, this will be an achievement given the fact that the BJP had won only for assembly seats in the 2009 assembly polls.
BJP in-charge Haryana Kailash Vijayvargiya: "People of Haryana wanted a change. Our party cadres and leaders worked very hard. The credit for our success has to go to Prime Minister Narendra Modi and BJP chief Amit Shah."
On the question of BJP having too many candidates aspiring to be the next chief minister in Haryana, Vijayvargiya said: "The party will collectively decide the next chief minister. He will be someone who will be acceptable to all sections in Haryana."
A party needs to win 46 seats to get a simple majority in the house.
Election officials counting the mass of votes polled Oct 15 said the Bharatiya Janata Party (BJP) was clearly ahead of its two main rivals, the Indian National Lok Dal (INLD) and the ruling Congress.
The INLD was ahead of others in 21 seats and the Congress in 14. The Haryana Janhit Congress (HJC) and others led in three and five seats respectively.
Chief Minister Bhupinder Singh Hooda was leading from his Garhi Sampla-Kiloi seat.
Union minister Sushma Swaraj's sister Vandana Sharma was also leading from the Safidon seat.
INLD leader and Hisar MP Dushyant Chautala was trailing over BJP candidate Premlata Singh by over 4,000 votes in the high-profile Uchana Kalan assembly seat.
Counting of votes for the 90 seats in Haryana began Sunday morning to decide the fate of 1,351 candidates, including 116 women.
A record 76.54 percent of Haryana's 1.63 crore electorate voted in the assembly polls this time.