Surachart, a former MP from the constituency, won an emphatic victory against the ruling party’s candidate.
Unofficial results after counting of ballots at all 280 polling stations at 8.30pm on Sunday showed Surachart winning comfortably, having polled 29,416 votes.
Move Forward Party candidate Krunphol Tiansuwan was second on 20,361 votes while Kla Party candidate Atavit Suwannapakdee came third on 20,047 votes.
Surachart said this victory came along with great responsibility to serve citizens, adding that he wanted to prioritise improving people's quality of life.
He vowed to hear citizens' complaints individually in order to deal with each issue properly.
“Once the Election Commission approves the by-election result, I am ready to work as an opposition MP to convey citizens' complaints to the government,” he said.
He added that he hopes the government will pay more attention to citizens' comments and interests.
Meanwhile, Pheu Thai Party leader Chonlanan Srikaew said this by-election had proved that citizens have witnessed the government's mismanagement and want to pave the future for their children, even though the number of people exercising their right to vote was low.
He said other political parties are competitors but not enemies and they should focus on how they can serve the people and create good things under a democratic form of government with the King as head of state.
He declined to comment on a Facebook post by expelled former Palang Pracharath Party secretary-general, Thamanat Prompow, which said: “The enemy of my enemy is my friend”, only saying that anyone working with Pheu Thai Party must not side with dictatorship in line with the party's vision.
He warned Deputy Prime Minister Prawit Wongsuwan that the by-election results are citizens' punishment to show that they do not support undemocratic political parties, adding that Palang Pracharath Party's MPs would be lower than 50 in the future.
He also asked Prime Minister General Prayut Chan-o-cha to dissolve Parliament and give the authority back to citizens to choose their next government.
“I will thank Prayut for his love for citizens if he dissolves Parliament,” he said. “It would be great if Prayut says he will remain in government no more than eight years which will end on August 3 this year.”
He added that Prayut should be concerned about the country and its citizens rather than his own position and the benefits to his team.