Lucknow: Samajwadi Party candidate Tej Pratap Singh today won the Mainpuri Lok Sabha bypoll by a margin of more than 3.21 lakh votes, continuing the party's two -decade-long dominance on the traditional turf of party supremo Mulayam Singh Yadav.

Tej Pratap, grand nephew of the SP supremo, defeated his nearest rival Prem Singh Shakya of BJP in the bypoll, which was necessitated after the resignation of Mulayam who also won from Azamgarh Lok Sabha seat.