Sumptoh tallied total of 2,756 votes in the by-election which was held last Friday.
The commission reported a poor turn out with 8,803 of the 18,587 of the registered voters voting.
There were 122 void votes.
The Chairman of the Electoral Commission, Edward Kaltamat, said just over 47 percent of the registered voters took part.
The Pentecost constituency seat was left vacant after the Supreme Court found former prime minister and Member of Parliament for Pentecost constituency Charlot Salwai guilty of perjury, early this year.
Salwai was recently pardoned by President Tallis Obed Moses which meant he could contest the by-election.
He polled the second highest number of votes with 2473.
Nine candidates contested the by-election.
Photo supplied Caption: MP-elect Blaise Sumptoh of Rural Development Party