A historian and populist firebrand who boasted about his brawls with soccer hooligans has narrowly won Poland’s presidential election, in a political upset that could torpedo the centrist government’s efforts to unspool the legacy of authoritarianism in the country.

Conservative Karol Nawrocki has won Poland's presidential election, winning 50.89% of the vote over liberal Warsaw Mayor Rafał Trzaskowski, who got 49.11%. Nawrocki will succeed Andrzej Duda as Poland's President when Duda's second term concludes on August 6.

A vote seen as a test of the power of populist nationalism in Europe was too close to call, with exit polls putting the two contenders neck and neck.