Turkish Prime Minister Recep Tayyip Erdogan has secured his place in history as Turkey's first directly elected head of state.
The result takes him a step closer to the presidential system he covets in a result his opponents fear heralds an increasingly authoritarian rule.
Supporters honking car horns and waving flags took to the streets in the capital Ankara after results on Turkish television said Mr Erdogan had won 52% of the vote, 13 points more than his closest rival and avoiding the need for a second round run off.
The chairman of the High Election Board confirmed Mr Erdogan had a majority, with more than 99% of votes counted, and said full provisional figures would be announced tomorrow.
"Today is a new day, a milestone for Turkey, the birthday of Turkey, of its rebirth from the ashes," Mr Erdogan told thousands of supporters in a victory speech from the balcony of his ruling AK Party headquarters in Ankara.
"I want to underline that I will be the president of all 77 million people, not only those who voted for me. I will be a president who works for the flag, for the country, for the people," he said.
He vowed a "period of reconciliation" and chastised those who accuse him of being dictatorial.
Around 53 million Turks were eligible to vote.
Turkey has emerged as a regional economic force under Mr Erdogan, who has ridden a wave of religiously conservative support to transform the secular republic founded by Mustafa Kemal Ataturk on the ruins of the Ottoman empire in 1923.
But his critics warn that a President Erdogan, with his roots in political Islam and intolerance of dissent, would lead the NATO member and European Union candidate further away from Ataturk's secular ideals.
After his victory is officially confirmed, Mr Erdogan will be sworn in as president on 28 August.
The AK Party was to begin meeting shortly to start deciding on candidates to replace him as premier and party leader.
Foreign Minister Ahmet Davutoglu is seen as a leading candidate.
Mr Erdogan's main rival in the election, Ekmeleddin Ihsanoglu, a former diplomat and academic who won 38.5% of the vote according to broadcasters CNN Turk and NTV, congratulated Mr Erdogan on the result in a brief statement.
Selahattin Demirtas took 9.7%, according to the TV stations - a result for an ethnic Kurd that would have been unthinkable just a few years ago as Turkey battled a Kurdish rebellion and sought to quell demands from the ethnic minority.
The voting turnout, which exceeded 89% in March local elections, appeared to be low, OSCE Parliamentary Assembly observer George Tsereteli told reporters.
Opinion polls had put Mr Erdogan far ahead of his two rivals competing for a five-year term as president.
Parliament has in the past chosen the head of state but this was changed under a law pushed through by Mr Erdogan's government.
He has set his sights on serving two presidential terms, keeping him in power past 2023, the 100th anniversary of the secular republic.
For a leader who refers frequently to Ottoman history in his speeches, the date has special significance.
He had, in campaign speeches, repeatedly vowed that his election would herald a "new Turkey."
But his vision left voters cold at one polling station in the capital Ankara, where many complained of deep polarisation under Mr Erdogan and said only his AK Party loyalists had benefited from changes in the past decade.
"The freedom that he says has increased is for his own supporters. You can only be free if you support him. He has polarised this country in a way nobody has before," one voter said.
Mr Erdogan has vowed to exercise the full powers granted to him by current laws, unlike predecessors who have played a mainly ceremonial role.
But he also plans to change the constitution to establish a fully executive presidency.
The current constitution, written under military rule after a 1980 coup, would enable him to chair cabinet meetings and appoint the premier and members of top judicial bodies including the constitutional court and supreme council of judges.