With ballots from 31 percent of polling stations counted late on Sunday, Fernandez, representing the governing Sovereign People Party (PPSO), secured 53.01 percent of the vote, News.Az reports, citing foreign media.
Alvaro Ramos of the centre-left National Liberation Party followed in second place with 30.05 percent, while former First Lady Claudia Dobles placed third with 3.9 percent.
Under Costa Rican electoral law, a candidate must win at least 40 percent of the vote to secure an outright victory and avoid a runoff election scheduled for April 5.
The 39-year-old Fernandez is the handpicked successor of incumbent President Rodrigo Chaves and campaigned on a pledge to continue his administration’s tough security agenda.
Rising crime has become a central issue in the historically peaceful Costa Rica, and the recent surge in violence is widely seen as a key factor influencing voters. While some critics blame Chaves’s government for failing to curb crime rates, others believe his confrontational leadership style offers the best chance to restore public safety.
Fernandez previously served as Chaves’s minister of national planning and economic policy and later as minister of the presidency.
Voters also elected members of the 57-seat National Assembly. Chaves’s party is expected to increase its representation, though it may fall short of the supermajority sought by both Chaves and Fernandez, which would allow the ruling party to appoint Supreme Court magistrates.
A total of 20 candidates contested the presidency, but preliminary and partial results showed that no contender other than Fernandez and Ramos surpassed the 5 percent threshold.
