With 82.6 percent of the votes counted, the results on Monday showed that Fujimori garnered 39.55 percent of the votes, giving her a wide 17-point lead over her closest rival, Xinhua news agency reported quoting the National Office of Electoral Processes.
Runner up Pedro Kuczynski, of the conservative Peruvians for Change party, secured 22.11 percent of the votes for a chance to compete in a June 5 presidential runoff against Fujimori.
Third-placed candidate Veronika Mendoza, of the left-leaning Broad Front, garnered 18.27 percent of the votes.
Another seven candidates shared the remainder of the votes.
Peru's election laws require a candidate to garner upwards of 50 percent of the votes for an outright win in the first round, otherwise the two leading candidates must face off in a runoff.
Nearly 23 million Peruvians, including 900,000 living abroad, registered to vote in Sunday's elections for a president, 130 members of Congress, and five representatives to the Andean Parliament, which takes office on July 28 for a five-year term.