Evangelical candidate Fabricio Alvarado recently vaulted into first place in the polls after he took a strong stance against gay marriage, which about two-thirds of Costa Ricans also oppose.
Carlos Alvarado, who is not related to Fabricio, is also a young candidate at just 38, a journalist by profession who began his political career as communications director for the Citizens' Action Party and served as labor minister under current President Luis Guillermo Solis.
Costa Ricans have voted in a presidential race shaken by an worldwide court ruling saying the country should let same-sex couples get married.
With almost 81 percent of ballots counted, evangelical candidate Fabricio Alvarado has 24.8 percent and governing party loyalist Carlos Alvarado has 21.6 percent.
If no candidate receives at least 40% of the 4 February vote, a runoff election with the top two candidates will happen in early April.
Banana entrepreneur Antonio Alvarez of the mainstream National Liberation Party had 19.9 percent, and Carlos Alvarado, a journalist, of the governing Citizen's Action Party had 19.3 percent.
"We propose the sovereignty of the family as the fundamental basis of society", Alvarado Munoz told supporters blowing plastic horns after the results were announced.
Both he and Carlos Alvarado appealed to backers of other candidates for support in the runoff.
Araya explained that this reactionary switch to defend Alvarado, who has vowed never to recognize gay marriage, has been facilitated by a lack of party allegiance in the country.
There are 3.3 million eligible voters in Costa Rica.
With so many candidates, a runoff seemed likely heading into the election.
"I am the one responsible for the electoral result", Alvarez said late Sunday.
Despite a history of progressive social policies, most Costa Ricans identify themselves as conservative, and evangelical Christianity has emerged as a religious and political force in recent years, reflecting similar changes across Latin America.
Some voters had other issues on their minds.
"Things have gone very well, the only thing I regret is the cold I have (.) The media portrayed a committed citizenry, we see a significant influx (of voters)", Sobrado said. "Everything is very expensive, and that would hurt us all".
All 6,612 Vote Collecting Boards (JRV) opened today at 06:00 hours, local time, in the general election in Costa Rica, where the president, two vice-presidents and 57 lawmakers of the Legislative Assembly will be chosen.