Lopez Aliaga, a hotel businessman who claims to practice celibacy and is known as "Porky," a famous cartoon character, led with 26.287% of votes following Sunday's election, the National Office of Electoral Processes (ONPE) said on its website.
Retired military officer Daniel Urresti, who is on trial for allegedly participating in the murder of a media worker in 1988, trailed with 25.379% of the votes.
"The trend is irreversible," political analyst and former head of the electoral office, Fernando Tuesta, said on Twitter.
Neither candidate has spoken so far.
Lopez Aliaga heads the conservative Popular Renovation party and is a staunch opponent of leftist President Pedro Castillo. The conservative politician ran for the presidency in 2021 and came third in those elections.
A win for Lopez Aliaga in Lima, where a third of the country's voters are concentrated, as well as likely victories by independents in regional votes in Peru's interior departments, would be a harsh defeat for the Marxist Peru Libre party that helped propel Castillo to the presidency.
"Its results have been negligible," said Alfredo Torres, executive president of the Ipsos Peru pollster, referring to the Marxist party's performance in the vote.
Insecurity, poverty and scarce public services are among the main issues to tackle for the upcoming mayor of the municipality of 10.5 million residents.
In all, some 13,000 authorities are set to be elected in the vote.
The results in the mining regions, which benefit from high revenues driven by taxes and royalties, will also be key since Peru is the world's second largest copper producer.
(Reporting by Marco Aquino; Writing by Anthony Esposito; Editing by Sandra Maler)
