The ruling Bharatiya Janata Party (BJP) retained the Tharali assembly seat in Uttarakhand by nearly 1,900 votes in the bypoll.
BJP candidate Munni Devi maintained a marginal lead since the beginning of counting on Thursday morning.
The bye-election in Tharali was necessitated after the death of BJP legislator Magan Lal Shah. The ruling party fielded his wife Munni Devi while Congress gave the ticket to former MLA Jeet Ram.
Three other candidates were in the fray from the seat, but they all lost their deposits.
The bypoll was seen as a litmus test for chief minister Trivendra Singh Rawat who took the reins of the state after last year assembly polls in which BJP grabbed 57 out of 70 assembly seats in the hill state.
The stakes were high in the closely fought election. The opposition Congress showed a united face to take on BJP.
Observers feel the sympathy wave for Magan Lal Shah worked in favour of his wife.