South Korea's president-elect Moon Jae-in gestures to supporters at Gwanghwamun Square in Seoul, South Korea, May 9, 2017. [Photo/Agencies]

SEOUL - Liberal Moon Jae-in won the South Korean presidential by-election as he gained votes enough to confirm victory, vote count results showed Wednesday.

With 91.3 percent of votes counted as of 3:07 a.m. local time (1807 GMT Tuesday), Moon garnered 40.5 percent, according to the national election commission.

Hong Joon-pyo of the conservative Liberty Korea Party won 24.8 percent. Even if the remaining uncounted votes go to Hong, he will not defeat Moon. It confirmed Moon's victory with certainty.

Ahn Cheol-soo of the centrist People's Party garnered 21.5 percent, trailed by Yoo Seong-min of the conservative Righteous Party with 6.7 percent.

Sim Sang-jung of the minor liberal Justice Party had 6.0 percent support.

Moon celebrated with jubilant supporters gathering at the Gwanghwamun square in central Seoul around midnight as his victory was assured by local media outlets in an early stage of vote count.

In the televised speech, Moon told supporters that he will become a president for all the people from Wednesday, saying he will become a president of unity, caring about those who did not support him in the election.

Before the speech, he told reporters at his party's building that he will achieve the two main goals of reform and unity people had wished for.

Four other major candidates made concessions to Moon, even before less than 10 percent of votes were counted. The concessions led local media outlets to predict an assured election of Moon.