A liberal South Korean political novice whose campaign reflected sentiments of the U.S. “Occupy Wall Street” movement has been elected mayor of Seoul.

The victory by newcomer and opposition activist-lawyer Park Won-soon became clear late Wednesday when ruling conservative Grand National Party candidate Na Kyung-won conceded defeat. Na's concession came with exit polls showing her trailing Park by more than nine percentage points.

In an accompanying statement, Na called the campaign a difficult fight, and said she accepted the defeat as a judgment against the ruling party.

Park ran as an independent with broad support from the opposition Democratic Party. In his victory address, he promised help for the citizens of the capital.

Officials reported a brisk voter turnout.

The win deals a fresh blow to ruling conservatives and is widely seen as a test of support for the parties ahead of parliamentary and presidential elections next year.

The ruling GNP had thrown its resources behind Na Kyung-won, and pre-election polls showed her with solid support from older voters. But those polls also showed her struggling to appeal to younger residents who were frustrated with GNP policies.