Punjab Chief Minister Parkash Singh Badal was leading in his pocket borough Lambi Assembly constituency.
89-year-old Badal was leading over his nearest rival Capt Amarinder Singh of the Congress as per early trends available.
Capt Singh, who is also fighting from his traditional stronghold Patiala, was leading in that seat.
Among the seats in which Congress was ahead included Amritsar Central, Tarn Taran, Khadoor Sahib, Jalandhar West (R), Chabbewal (R), Anandpur Sahib, Fatehgarh Sahib, Dharamkot, Baluana (Reserve), Gidderbaha, Faridkot, Rajpura and Patiala seats.
Congress, which has been out of power in Punjab for past ten years, is seeking to wrest power from the ruling SAD-BJP combine.
Aam Aadmi Party, which made the contest triangular this time, contested its maiden assembly election in Punjab.
Ruling Shiromani Akali Dal-BJP was ahead in Lambi, Bhagapurana, Moga, Majitha seats, among other seats, as per early trends.
AAP was ahead in Bathinda Urban, Mansa, Bhadaur (R) and Mehal Kalan (R) seats.
From Gidderbaha, All-India Youth Congress President Amarinder Singh Raja Warring was leading. In the Majithia seat, SAD's Bikram Singh Majithia was leading.
Congress' Manpreet Badal was trailing AAP candidate Deepak Bansal from Bathinda Urban as per initial trends.
Congress leader Sunil Jakhar was trailing BJP's Arun Narang by a margin of 1487 votes from Abohar segment.
Congress Navjot Singh Sidhu was leading over AAP candidate by a margin of 2691 votes from Amritsar-East segment.