Peru’s presidential runoff Sunday was too close to call as preliminary results came in, setting the stage for days or potentially weeks of counting. A quick count showed the two candidates locked in a statistical tie, though the leftist candidate, Roberto Sánchez, had a slight edge.
The race pitted Mr. Sánchez, a leftist lawmaker and political heir to a jailed former president, Pedro Castillo against Keiko Fujimori. Ms. Fujimori’s father was Alberto Fujimori, an authoritarian president in the 1990s who was credited with dismantling brutal leftist rebel groups, but at the cost of unraveling Peru’s democracy and earning a 25-year prison sentence for human rights abuses.
Mr. Sánchez spent the campaign’s final weeks pivoting toward the center as he sought to court undecided moderates. He promised to maintain fiscally responsible policies, protect private property and preserve the central bank’s autonomy.
Ms. Fujimori, by contrast, catered to her right-wing base as a tough-on-crime candidate, and framed Mr. Sánchez as a communist and a would-be authoritarian who would torpedo private investment.
The race comes as an anti-incumbent wave shifts Latin America toward the political right Law-and-order governments have already transformed Argentina, Bolivia, Chile and Ecuador.
Peru’s election follows years of political volatility and a punishing crime wave under a succession of presidents. Mr. Sánchez is tied to the turbulent record of recent leftist governments, while Ms. Fujimori embodies a conservative establishment deeply resented in rural and Indigenous regions.
A quick count by the polling firm Ipsos, which samples vote tallies from a representative selection of polling stations, showed Mr. Sánchez with 50.3 percent and Ms. Fujimori with 49.7 percent.
Though the margin of error leaves the race in a statistical tie that could still flip, the Ipsos quick count has correctly predicted every Peruvian runoff winner since 2001. Immediately after its release Mr. Sánchez appeared on a balcony before a cheering crowd, pumping his fist and striking a celebratory pose alongside his running mate.
He celebrated the “significant lead” but urged supporters to “defend the vote” until a “100 percent final result.”
Ms. Fujimori in a speech said “there is no winner in this race” and that “it would be irresponsible to determine the result based on a sample,” adding that she would respect the final tally.
The official count, with more than 56 percent of the vote counted, showed Ms. Fujimori in the lead with 53 percent and Mr. Sánchez with 47 percent, but it did not yet reflect balloting in Sánchez strongholds.
Electoral officials said at a news conference that the final audited count would take about a month to complete, raising the possibility of an extended period of political uncertainty.
The tensions surrounding the vote set off fears of voter suppression Sunday morning after isolated reports of pre-marked or damaged ballots emerged. Left-leaning social media accounts said that ballots pre-marked for Ms. Fujimori had surfaced in an affluent Lima suburb, while right-wing networks said ballots rigged for Mr. Sánchez had been found in the rural highlands.
Peru’s independent civil rights office briefly escalated anxieties by calling the irregularities an “attempted fraud” before reversing course hours later to say that the flawed ballots had affected only about 20 polling booths nationwide with no adverse impact on the vote.
Seeking to project an image of control at a Sunday afternoon news conference, Peru’s top electoral officials rejected the possibility of systematic fraud and said a handful of isolated irregularities had been quickly resolved.
The head of the attorney general’s office on crime prevention Alfonso Barrenechea told local news media that 7,000 representatives were policing the vote. He said that the system’s guardrails had successfully handled localized threats, and that investigators had intercepted and replaced between 60 and 90 manipulated ballots at 12 polling stations nationwide.

