TEHRAN, Young Journalists Club (YJC) - The 62-year-old former head of the domestic security service made the claim in the early hours of Sunday in the presence of current president Mohamed Ould Abdel Aziz, his supporters and journalists.
The ballot is the first in Mauritania's coup-strewn history that looks set to see an elected president complete his mandate and transfer power to an elected successor, although the opposition has raised concerns the vote could perpetuate a government dominated by military figures.
Some 1.5 million people were entitled to vote Saturday in the vast, predominantly Muslim state, which is approximately twice the size of France and has a population of just 4.5 million.
Preliminary official results had been expected at the start of this week.
But according to a source at the Independent National Electoral Commission (CENI), Ghazouani had won 50.56 percent of the votes after 80 percent of the votes had been counted.
"There is only 20 percent left (to count), but that will not change the final result," journalists quoted Ghazouani as saying.
"Our candidate will win in the first round of voting," ruling party spokesman Sidi Ould Domane had told reporters just before voting ended.