Romano Prodi's narrow victory in the upper house of parliament in Italy has been confirmed by an appeals court.
Mr Prodi can now begin the process of forming a new government
The certification of overseas ballots was the final check needed to confirm Mr Prodi had won the closest election in the history of the Italian Republic.
A court had already confirmed that Mr Prodi's coalition had won a majority in the lower Chamber of Deputies.
The 66-year-old will now form the next government although Silvio Berlusconi still refuses to concede defeat.
Over the past week, regional appeals courts have confirmed preliminary data from the interior ministry that gave Mr Berlusconi's centre-right bloc 155 Senate seats compared with 154 for Prodi's coalition.
On Saturday, the electoral office for the foreign vote, which is part of Rome's court of appeals, confirmed that four of the six seats chosen by Italians living overseas went to Mr Prodi's coalition, one to Mr Berlusconi's allies and one to an independent party.
That gave the total Senate breakdown: 158 for Mr Prodi's block, 156 for Mr Berlusconi and one independent - the majority Romano Prodi needed to win the house, reports the Associated Press news agency.
Mr Berlusconi is still refusing to concede defeat
But Mr Prodi will have to wait until after the election of a new Italian head of state in mid-May before he can actually begin to appoint ministers from among his centre left coalition supporters and begin to run the country.
Despite this, Mr Berlusconi has remained defiant.
Speaking to supporters in the northern city of Trieste, he said he had no intention of making any formal telephone call to Mr Prodi conceding defeat, as he believes the new centre left coalition will quickly become unglued, reports the BBC's David Willey in Rome.
On Thursday the US followed Britain, France and Germany in recognising Mr Prodi's victory.