According to unofficial and unconfirmed results from all of 120 polling stations, Sanaullah won the by-polls with 21850 votes to his credit.
He was followed by Jamat e Islami (JI) nominee Malik Azam who secured 15009 votes.
The polling began at 8am and will continue till 5pm without any break. As many as 120 polling stations have been set up in the constituency.
A firing incident was reported at a polling station in Shagla, resulting panic among the voters. The polling process was also stopped after the incident.
Four candidates are in the run, including two independent candidates Jamshed Khan and Shah Faisal . However, close contest is expected between Malik Azam Khan of Jamaat-e-Islami and Sahibzada Sanaullah of PPPP.
The seat fell vacant after disqualification of former MPA Behram Khan of Jamaat-e-Islami in a fake degree case in July.
At least 90 polling stations out of the total 120 have been declared as most sensitive and 30 as sensitive.
The local administration has deployed 7,000 police and Levies personnel deployed to guard the polling stations.