Veteran politician Beji Caid Essebsi has been confirmed as winnerof Tunisia's first free presidential poll.
He secured 55.68% of the vote in Sunday's run-off, defeating caretaker president Moncef Marzouki (44.32%), the head of the electoral commission said.
Mr Marzouki, a 67-year-old former exile, earlier refused to admit defeat.
Mr Essebsi, 88, has urged all Tunisians to "work together" for stability but critics say his win marks the return of a discredited establishment.
They point out that he served under President Zine el-Abedine Ben Ali, who was ousted in 2011 after the Arab Spring revolution triggered uprisings across the region.
Mr Essebsi was also in the cabinet of Tunisia's first post-independence leader, Habib Bourguiba.
Earlier on Monday, police fired tear gas in the southern city of Hamma to disperse hundreds of demonstrators who burned tyres in protest at Mr Essebsi's victory.
The results of the run-off vote were announced by the head of the electoral commission, Chafik Sarsar, who was visibly emotional.
It is the first time Tunisians have been able to vote freely for their president since independence from France in 1956.