The ruling BJP forged ahead of its rivals in 12 of the 28 constituencies in Karnataka, according to the initial trends.
The Congress was leading in five constituencies and JDS in two.
JDS supremo H D Deve Gowda was racing ahead of his rival in his home turf Hassan.
Former Chief Minister S Bangarappa (Cong) was trailing behind B Y Raghavendra (BJP), son of Chief Minister B S Yeddyurappa in Shimoga.
Deve Gowda's son and former Chief Minister H D Kumaraswamy had established a lead over BJP's C P Yogeshwar in Bangalore Rural constituency.
Congress leader and former Chief Minister Dharam Singh was leading in Bidar.