Turkey's long-standing leader Recep Tayyip Erdogan has won a new five-year term after securing outright victory in the first round of a presidential poll, BBC reported.
Election authority chief Sadi Guven said the president "received the absolute majority of all valid votes".
State media reports put Mr Erdogan on 53% with 99% of votes counted, and his closest rival Muharrem Ince on 31%.
The opposition is yet to officially concede but said it would continue its democratic fight "whatever the result".
It had earlier cast doubt on results being broadcast by state media. Final results will be announced on Friday.
The polls were the most fiercely-fought in many years, and Mr Erdogan is set to assume sweeping powers under a new executive presidency.
He has presided over a strong economy and built up a solid support base by investing in healthcare, education and infrastructure.