PTI dominates Punjab Assembly with 179 seats, whereas PML-N has 164 seats in the house.
A support of 186 members, in the 371-members House, is needed for a party to form a new government in the province.
Seven members of the Pakistan Peoples Party remained present in the house but did not cast vote.
The newly-elected chief minister comes from one of the most backward areas of Punjab, the tribal area of Dera Ghazi Khan division, some 400-km from Lahore, the provincial capital.
In his maiden address to the provincial assembly, 49-year-old Buzdar vowed to focus on neglected areas of the province.
"I belong to an underdeveloped area myself. Our priority is good governance and ending corruption," he said, adding that he will take forward Imran Khan's vision.
He thanked Prime Minister Khan for nominating him for the top post.
"There has been no electricity in my area. We will try to break the status quo. I will bring forth the best time to fight corruption and poverty. We will bring reforms in police," he said.
The voting for the top post was delayed by nearly three hours as the session was scheduled to be started at 11am. Shortly after the speaker commenced the session, PML-N lawmakers staged a protest raising slogans "rigged polls", referring to the July 25th general elections.
Prime Minister Khan had strongly backed Buzdar's candidature, saying the candidate understands the problems of the people of neglected areas and will strive to ensure their uplift as chief minister.
"I have done my due diligence over the past 2 weeks and have found him to be an honest man. He has integrity and stands by my vision and ideology of Naya (new) Pakistan," Khan had said.
Buzdar, a political science graduate from Bahauddin Zakriya University in Multan, first got elected as the member of Punjab Assembly in 2002 on the platform of then military ruler Gen Pervez Musharraf's party PML-Q.
In 2013, he joined PML-N and contested on its ticket but lost. He had joined Khan's party last year and won the July 25 poll.
Opposition alleged that Buzdar has been involved in corruption and a murder case in which he got himself exonerated from charges after striking a deal with victims' families and paying them Rs 7.5 million blood money (diyat).
Buzdar denied any corruption or other cases against him. "All allegations against me are baseless," he said.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)