RJD today won the Jokihat assembly seat in a bypoll in Bihar defeating JD(U) by a huge margin of 41,000 votes.
RJD candidate Shahnawaz Alam defeated Murshid Alam of JD(U) by over 41,000 votes, Deputy Chief Electoral Officer Baiju Nath Kumar said.
Jokihat seat in minority muslims dominated Araria district of Bihar was held by JD(U) during the 2015 state elections.
By-election to the assembly seat was necessitated by the resignation of sitting MLA Sarfaraz Alam, the elder brother of the RJD candidate in March this year, who went on to win the by-poll for Araria Lok Sabha seat on an RJD ticket.
Their father Taslimuddin, whose death had necessitated the Araria by-poll, had represented Jokihat for a record five times.
The Jokihat bypoll defeat has come as a jolt to Chief Minister Nitish Kumar who dumped RJD and Congress last year to join hands with BJP to form a new coalition government in Bihar.
JD(U) had registered three consecutive wins at Jokihat before today's defeat.