The Trinamool Congress chief greeted JD(S) leaders H D Deve Gowda and H D Kumaraswamy and the Congress.
"Democracy wins. Congratulations Karnataka. Congratulations DeveGowda Ji, Kumaraswamy Ji, Congress and others. Victory of the 'regional' front (sic)," she said in a tweet.
Mr Yeddyurappa's resignation will pave the way for formation of a government led by JDS state chief H D Kumaraswamy, who has the backing of the Congress. The newly formed alliance has claimed support of 117 MLAs in the 224-member House with an effective strength of 221.
Polling for two seats was not held due to various reasons, while Mr Kumaraswamy won from two places.