"If the (electoral) jury analyzes this, the election will be flipped, dear friends," Fujimori told thousands of supporters, many waving Peru's red-and-white flag. "I'm the sort of person who never gives up."
Front-runner Pedro Castillo, a member of the left-wing Free Peru party, is close to being named the Andean country's next president, despite Fujimori's unsubstantiated claims of fraud, as the count from the second round of voting earlier this month nears an end.
Castillo, an elementary school teacher who was raised in an impoverished village, was leading the count by 50,000 votes on Saturday evening, with only around 16,000 votes remaining to be counted.
But Fujimori this week has increasingly doubled down on allegations of fraud, saying supporters of Castillo stole votes in rural areas where she got no votes. International observers have said there is no evidence of fraud and that the election was clean.