BJP has so far won 14 seats and is maintaining leads in 34 constituencies as the counting for the Assembly elections was drawing to a close. Its rival Congress has won 12 seats and was leading on 28 seats.
"It is a historic day and I thank people of the state for BJP's hat-trick," Singh told reporters here.
Singh, who has been the Chief Minister of the state for consecutive two-term, said people have voted for his pro-development work and welfare measures.
Singh got 86,797 votes while Alka could get 50,931 votes.
Alka is wife of Congress leader Uday Mudliar, who was killed in naxal attack in Darbha valley under Bastar region May this year.