Gripped by cholera and struggling to recover from last January's devastating earthquake, Haiti faces a choice between ruling party candidate Jude Célestin, or former first lady Mirlande Manigat.
Angry protests Wednesday greeted the announcement that Célestin, President René Preval's handpicked protege, had made it through to the presidential run-off by fewer than 7,000 votes.
Tasked with rebuilding efforts after the quake, Célestin has struggled to shake off the image of being too close to the unpopular president.
Opinion polls suggest that Célestin, who studied engineering in Switzerland, is not popular on the street.
Meanwhile Manigat, a founding member of the opposition Rally of Progressive National Democrats, has made education reform a key plank of her campaign, promising to give Haiti's youth universal access to public schooling.
She studied at the Sorbonne and the Paris Institute of Political Studies, Sciences Po.
"Haitians do not want continuity. They want change, to see a rupture from the past," she told the news agency AFP.