Lebanon's anti-Syrian opposition bloc has won all 28 seats in the final voting round, clinching a majority in parliament, official results show.
Saad Hariri is now pledging a programme of sweeping reforms
The victory of the alliance led by Saad Hariri was confirmed by Interior Minister Hassan Sabeh.
The opposition will now have 72 seats in the 128-seat legislative body.
The election - held in four stages - was the first since Syrian troops pulled out of the country in April after 29 years.
The BBC's Jim Muir in Lebanon says the opposition's victory will allow it to push ahead more easily with dismantling what it calls the security state set up by the Syrians.
In Washington, US State Department spokesman Adam Ereli said the election was an important step toward Lebanese freedom and democracy.
The polls were also hailed by the UN and the EU, although the latter expressed its concern over what it said were attempts of vote-buying.
In a joint statement after their Washington summit, the US and the EU said they would consider calling an international conference to solicit support for the new Lebanese government.
The Hariri factor
Mr Hariri - the son of former Prime Minister Rafik Hariri, who was killed in a car bomb in February - pledged sweeping reforms after his poll triumph, saying that people had voted for change.
"There should be administrative and financial reforms, anti-corruption measures and economic, development and social programmes," he said.
Mr Hariri promised to set out a full policy programme within a week, dedicating his victory to his late father.
"I owe my father everything," he said.
Mr Hariri declined to speculate whether he would seek post of prime minister.
In the fourth and decisive voting round in northern Lebanon, Mr Hariri's bloc was challenged by the pro-Syrian former army general Michel Aoun.
The absence of Syrian control was a clear feature of the elections - but influence is another matter, not so easily excluded, our correspondent says.
The two main Shia movements regarded as close to Damascus - Hezbollah and Amal - won all the seats in the south and others elsewhere in the earlier voting rounds.
Key figures widely regarded as symbols of the Syrian era - such as Shia speaker of parliament Nabih Berri and Maronite Christian President Emil Lahoud - may well survive the changes, our correspondent says.
Damascus ended its nearly 30-year deployment in Lebanon in response to street protests and international pressure triggered by Hariri's assassination.