The 14-month-old JDS-Congress coalition in Karnataka lost the trust vote on Tuesday weeks after its 16 legislators and two independent lawmakers withdrew their support.
In the 225-member Karnataka Assembly, 20 lawmakers were not present in the House for the floor test. The BJP won 105 votes to the Congress-Janata Dal Secular's 99 in the trust vote.
HD Kumaraswamy stepped down as the chief minister. BJP's BS Yeddyurappa is set to become the chief minister for the fourth time as rival Congress lost another state under its belt.
Reacting to the fall of the coalition, the BJP tweeted that it was a "Game of Karma".
In a statement, the Congress attacked the BJP over "horse tradings". "The sabotage of a duly elected government in Karnataka carried out by the BJP is one of the most heinous and subversive instances of blatant political horse tradings the country has ever witnessed," the statement read.