The BJP's candidates were declared victorious in Bengaluru North, Bellary (ST), Bidar, Chikkaballapur, Haveri, Koppal, Shimoga and Uttara Kannada.
The saffron party is also leading in Bagalkot, Bangalore Central, Bangalore South, Belgaum, Bijapur (SC), Chikkodi, Chitradurga (SC), Dharwad, Davanagere, Dakshina Kannada, Gulbarga (SC), Kolar, Mysore, Raichur (ST), Tumkur and Udupi-Chikmaglur.
The Congress is leading in Bangalore Rural and Chamarajanagar (SC) in the old Mysore region, while the JD-S retained Hassan with its candidate Prajwal Revanna defeating A. Manju of the BJP by 1,41,324 votes after all 24 rounds of counting.
Prajwal is the grandson of JD-S supremo H.D. Deve Gowda and son of state PWD Minister H.D. Revanna, elder brother of Chief Minister H.D. Kumaraswamy.
An independent - south Indian multi-lingual film actress Sumalatha Ambareesh, backed by the BJP - is leading in Mandya over JD-S contestant Nikhil Kumaraswamy by 1,17,226 votes after 18 of the 22 rounds.
Nikhil is son of Kumaraswamy and another grandson of JD-S supremo H.D. Deve Gowda.
Deve Gowda was narrowly trailing BJP's G.S. Basavaraj in Tumkur by 12,387 votes after all the 19 rounds of counting.
"The declaration in Tumkur will be made after verifying the votes counted in the EVMs with slips of the Voter Verified Paper Audit Trails (VVPAT) randomly from every five Assembly segments of the Lok Sabha constituency, as directed by the Supreme Court on April 8," the official said.
Congress leader in the outgoing Lok Sabha Mallikarjun Kharge was also trailing BJP's Umesh Jadav in Gulbarga reserved seat by 62,201 votes after seven of the 21 rounds of counting so far.
BJP's first-time contestant and young turk Tejaswi Surya was leading by 3,24,940 votes against Congress Rajya Sabha member B.K. Hariprasad in the high-profile Bangalore South after 20 of the 23 rounds so far.
The BJP contested in 27 seats while ruling allies Congress fought in 21 and the JD-S in seven seats as part of their pre-poll alliance seat arrangement.
In Bangalore Central, BJP's two-time winner P.C. Mohan overtook his Congress rival Rizwan Arshad after trailing in the initial rounds.
In the 2014 general election, the BJP won had 17 seats, the Congress nine and JD-S won two.