NCP workers celebrate their party's success in Bhandara–Gondiya Loksabha by-elections, outside their party office, on Thursday. Pic/PTI

Ahead of next year's general elections, a united Opposition got a major boost on Thursday when it delivered a huge blow to the BJP, defeating it in the Kairana Lok Sabha by-election in Uttar Pradesh and Bhandara-Gondiya in Maharashtra, while the saffron party managed to retain the Palghar parliamentary seat and win only one out of the 10 assembly seats in 10 states.