The BJP candidate, Jagruti Patel, polled 11,129 votes in ward no. 116, while the Sena nominee, Minakshi Patil, got 6,337 votes, an official of the Brihanmumbai Municipal Corporation (BMC) said.
The by-election was necessitated after the death of Congress corporator Pramila Patil on April 25.
With the latest victory, the BJP's tally in the 227-member BMC has risen to 82, while that of the Sena remains at 84.
The Congress had fielded Pramila Singh as its candidate.