Albania's ruling coalition of outgoing Prime Minister Sali Berisha and its leftist opposition led by Socialist Edi Rama both claimed victory in Sunday's general election.
The first official preliminary results were expected only on Monday.
"The Renaissance has won," Rama told joyous supporters of his leftist coalition.
Just a few blocks away, Berisha told reporters in his Democratic party headquarters that he was "convinced of our great victory."
The Central Electoral Commission said it had allowed the vote to be extended after the 1700 GMT closing time as many people were still waiting to cast their ballots.