Fahad Ahmad, Sharad Pawar's party candidate, lost to Sana Malik, of rival NCP faction led by Ajit Pawar, by a margin of 3,378 votes in Anushakti Nagar.
Anushakti Nagar is a part of the Mumbai South-Central Lok Sabha constituency.
Sana Malik is the daughter of incumbent legislator Nawab Malik. Mr Ahmad, who was once the "yuva" neta of Akhilesh Yadav-led Samajwadi Party, crossed over to Sharad Pawar's party days before polls. Mr Ahmad is married to Bollywood actor Swara Bhasker.
"We accept the election result. Congratulations to Ms Sana Malik. I hope you will serve our constituency without discrimination or favour. Thanks to all my voters, supporters & team. I will always stand by you and be there for you. This is just the beginning," Mr Ahmad posted on X.
After leading for several rounds of vote-counting, when Mr Ahmad started trailing his wife actor Swara Bhasker questioned the voting machines or the EVM.
Taking to X, Ms Bhasker said Fahad Ahmad had been leading in Mumbai's Anushakti Nagar seat until EVMs with 99 per cent charge were opened.
"How can machines that have been voted on ALL day long have 99% charged batteries? Why do all 99% charged batteries give votes to BJP and its allies?" Ms Bhasker asked, tagging the Election Commission and top leaders of the Maha Vikas Aghadi.
Earlier, as he was trailing Mr Ahmad called it "rank manipulation" and sought a vote recount.
"After round 16 and a steady lead in all rounds... EVM machines that were 99% charged were opened and BJP supported NCP Ajit Pawar candidate took a lead .. @ECISVEEP@SpokespersonECI this is rank manipulation. We demand a recount of rounds 16, 17, 18 and 19," he said.
The 32 year-old Fahad Ahmad, a graduate of Aligarh Muslim University and Tata Institute of Social Sciences, is a native of Bareilly in Uttar Pradesh.
The BJP-led Mahayuti alliance won a decisive victory in the state polls.
The polling for 288-member Maharashtra assembly took place on Wednesday, with a turnout of over 66 percent, surpassing the 61 percent recorded in the 2019 elections.
