Democrat Sarah Palin lost to Mary Peltola for the Alaska congress seat.
Wednesday marked Peltola's 49th birthday, making her the first woman and Alaska Native elected to the House.
Sarah Palin lost to Peltola by three percentage points, 51.5% to 48.5%, in the last round of voting.
The controversial Palin is prevented by Peltola's triumph from making an instant comeback into the national political arena.
Although Alaska's special election took place earlier this month, the results of all the mail-in ballots weren't tallied until Wednesday.
Voters' ballots were redistributed to the candidate who received their second-place votes after the Republican Nick Begich III finished third in the race.
Even though Palin had harsh words for her campaign rival, Peltola, whom she referred to as a "sweetheart," was spared during the campaign.
According to Peltola, she was optimistic that the new system would enable the election of more moderate politicians.
Before the election, Peltola stated.
"And my goal is that we avoid truly radical candidates and politicians," he continued.