There were cross-party appeals in support of Rutuja Latke.
The BJP today withdrew its candidate from an important by-election in Mumbai - an unusual move that ensures rival Uddhav Thackeray's victory without contest.
Rutuja Latke, the candidate of Uddhav Thackeray's Sena faction, now has a guaranteed win from Andheri (East) in Mumbai, the constituency of her husband and Shiv Sena MLA Ramesh Latke, who died earlier this year.
Her BJP rival Murji Patel dropped out today from the bypolls to be held on November 3.
"We are taking back our candidate as we want Latke Ji to win the elections. BJP will be contesting the seat in the 2024 elections," said the BJP's Chandrashekhar Bawankule.
The BJP's move followed two unexpected appeals, from Uddhav Thackeray's estranged cousin Raj Thackeray and from an MLA of Maharashtra Chief Minister Eknath Shinde's Sena faction.
Raj Thackeray wrote to BJP leader and Deputy Chief Minister Devendra Fadnavis urging him to withdraw his party's candidate so Rutuja Latke could win unopposed.
"Late Ramesh Latke's wife Rutuja Latke is contesting the election after her husband's death. I have been a witness to Ramesh Latke's journey from a worker to MLA. His wife becoming an MLA after his death would be a tribute to the departed soul," the Maharashtra Navnirman Sena (MNS) chief wrote in his letter addressed to "Dear friend Devendra".
"I think by doing this we are paying tribute to the late representative of the people. To do so is also in line with the great culture of our Maharashtra. I hope you will accept my request," Raj Thackeray said.
Responding to his letter, Mr Fadnavis said he could not take the decision alone.
Later, Pratap Sarnaik, an MLA of Eknath Shinde's Sena, wrote to the Chief Minister that the BJP should not field a candidate against Rujuta Latke as a tribute to her late husband. All parties should back Ms Latke and let her win the election, Mr Sarnaik told his party boss.
NCP Chief Sharad Pawar also appealed to the BJP to withdraw its candidate.
"The term for the new member (MLA) will be just one-and-half years. The bypoll is being held because of the unfortunate death of Ramesh Latke. His contribution must be taken into consideration," Mr Pawar said.
The NCP and team Thackeray said the BJP pulled out its candidate as it knew it would lose the byelection.
"The BJP and Shinde faction may have realised that they would face a very humiliating defeat against Latke. We appreciate that better sense prevailed finally," said NCP leader Jayant Patil.
Sanjay Raut, a close aide of Uddhav Thackeray, said the BJP had already decided to drop out of the race and Raj Thackeray's letter was "scripted".
Team Thackeray had earlier accused Eknath Shinde's faction of trying to sabotage their candidate by influencing the Mumbai civic body to delay her resignation.
Ms Latke, who worked in the Brihanmumbai Municipal Corporation (BMC) as a clerk, could file her nomination for the bypolls only after a court ordered the civic body to accept her resignation.