Socialist Party candidate Ion Ceban won the mayoral race for Chisinau in the elections on Sunday with 52.39 per cent of the votes cast.
The pro-European candidate and co-president of the ACUM bloc, Andrei Nastase, scored 48.61 per cent.
According to data from the Central Election Commission, Ceban won the votes of 123,807 citizens, while Nastase got 112,513 votes.
Moldova faces a fresh political crisis after the Constitutional Court declared the new government, led by the pro-European leader Maia Sandu and sworn in on Saturday, illegal.
The Court, which is widely seen as heavily influenced by the Democratic Party, also ordered the dissolution of parliament, which means new legislative elections must be held.
The pro-European political bloc ACUM and the pro-Russian Socialist Party, PSRM, held talks on Tuesday about the possibility of establishing a new parliamentary majority in Moldova after almost three months of political deadlock.
The negotiations started after US, EU and Russian officials visited Moldova on Monday.
The pro-Russian President of Moldova, Igor Dodon, and supporters of the Socialist Party on Thursday led a march to celebrate the 75th anniversary of the Red Army victory over Nazi Germany and the end of World War II.
"It must be an equal celebration for everybody. Victory Day is a celebration of all citizens in Moldova," Dodon said.
Moldova does not plan to negotiate a new gas contract with Russian energy giant Gazprom but will wait instead for construction of a link to the European energy network, Interfax quoted Moldovan Economy Minister Chiril Gaburici as telling a television talkshow on Monday.
Chisinau's current contract with Gazprom was signed in 2008 and runs until the end of 2019.