Before his legislative assembly debut this time, he has been elected twice as a Member of Parliament from Sangrur.
The incumbent Congress could win only 18 seats, with Chief Minister Charanjit Singh Channi losing both seats he contested -- Chamkaur Sahib as well as Bhadaur.
Counting began at 8 am under multi-tier security cover. At first, postal ballots will be counted and then EVMs opened.
The Congress is banking on decisions like reducing electricity tariff and fuel prices, taken during current CM Charanjit Singh Channi's 111-day tenure.
Counting of votes for the bypolls in Delhi, Uttar Pradesh, Punjab, Tripura, Andhra Pradesh and Jharkhand will be taken up on Sunday.
Mann, 48, is a two-time MP from Sangrur and is the party's state unit chief.
Two persons were injured in a clash which took place between AAP and Congress workers at Sultanpur village in Sangrur district.
Addressing public rallies at Barnala chowk and Bhawanigarh in Sangrur, the chief minister vowed to do whatever it takes to protect the farmers and the state from the 'devastating' effects of the 'black laws'.
The high-voltage campaign for the February 4 assembly elections in Punjab came to an end on Thursday evening following hectic campaigning by various political parties.
The assembly polls are seen as a test of Prime Minister Narendra Modi's popularity, especially in the wake of demonetisation.
Lashing out at Kejriwal's "confrontationist attitude", she said, people of Delhi were "regretting" what they had done one year ago.