Hungary's opposition Tisza party, led by Péter Magyar, has achieved a dramatic election victory over Prime Minister Viktor Orbán's ruling Fidesz party, according to reports from Budapest.

Celebrations took place along the Danube riverbank opposite the Hungarian parliament building, with crowds chanting pro-Hungarian and pro-European slogans. The victory represents a significant shift in Hungarian politics after years of Fidesz rule under Orbán, who has been in power since 2010.

The election results have implications for European Union relations, as Orbán's government has been a frequent critic of EU policies and has maintained closer ties with Russia than other member states. Hungary under Orbán has also opposed several EU sanctions against Russia and has taken positions that have put it at odds with other European capitals.

A concert described as a 'system-changer' event took place at Heroes' Square in Budapest on Friday evening, drawing large crowds of young people. The same square was historically significant during Hungary's 1989 transition from communist rule, when Orbán himself was a young opposition leader calling for democratic reforms.

The victory comes at a time when Hungary's relationship with the European Union has been strained over issues including rule of law concerns and disagreements over migration policy. The election outcome could signal a potential shift in Hungary's foreign policy orientation and its relationships with both the EU and neighboring countries.