In a straight contest, the Bharatiya Janata Party's Anil Dhiman, a physician by profession, defeated Promila Devi of the Congress by a margin of 8,290 votes in the by-election held on April 9 for the constituency in Hamirpur district.
Dhiman polled 24,434 votes against 16,144 votes of Promila Devi, an Election Commission official told IANS.
The by-poll was necessitated following the death of two-time former Cabinet Minister I.D. Dhiman, who had won six consecutive elections from this constituency.
Anil Dhiman, who was leading in all the 12 rounds of vote count, is the son of the late I.D. Dhiman.
The election saw over 63 per cent voting.
Leader of Opposition and two-time BJP Chief Minister Prem Kumar Dhumal told reporters that this victory was a clear indication that the party was going to form the next government in the state.
Assembly elections in the state are due in December.
However, West Bengal's ruling Trinamool Congress on Thursday retained the Kanthi Dakshin assembly seat in Purba Medinipur district with an impressive margin while the BJP finished second.
Trinamool candidate and former Health Minister Chandrima Bhattacharya trounced Bharatiya Janata Party's Sourindramohan Jana by over 42,000 votes.
Bhattacharya got 95,369 votes and Jana 52,843. Trinamool had won the seat by over 34,000 votes in 2016. Bhattacharya had lost from Dum Dum (North) in the 2016 assembly polls.
Communist Party of India candidate Uttam Pradhan, who had finished second in 2016, lost his security deposit this time.
In 2016, the Left Front had a tie-up with the Congress. The BJP had then taken the third place.
The Congress also put up a poor show, with its nominee Nabakumar Chanda getting only around 1.3 per cent of the votes.
The by-election was held on April 9.
The seat fell vacant after Trinamool legislator Dibyendu Adhikari was elected to the Lok Sabha from Tamluk in 2016.
In Delhi, Deputy Chief Minister Manish Sisodia on Thursday said that Delhi assembly's Rajouri Garden constituency voters were angry over AAP lawmaker Jarnail Singh's resignation to contest the Punjab assembly elections, which led to the party's poor show in the April 9 by-poll.
"People in the Rajouri Garden assembly constituency were angry after Jarnail Singh resigned... We tried to make them understand, but seeing the trends it seems they are still angry with the AAP," Sisodia told reporters outside his official residence.
However, he said it was just a by-poll, and added "we will keep preparing for the coming elections".
The poll panel said on its website that BJP candidate Manjinder Singh Sirsa won with 40,602 votes after the final and 17th round of ballot counting was held here.
The Congress' Meenakshi Chandela polled 25,950 votes while ruling AAP's Harjeet Singh stood at a distant third with 10,243 votes in this assembly constituency in Delhi.