The two surviving candidates in Egypt's presidential election have appealed for support from voters who rejected them as polarising extremists in the first round, as they faced a new challenge from the third runner-up.
Ahmed Shafiq, Hosni Mubarak's last prime minister, vowed he would not revive the old authoritarian regime as he sought to cast off his image as an anti-revolution figure, while the Muslim Brotherhood's candidate Mohammed Morsi reached out to those fearful of hardline Islamic rule and the rise of a religious state.
Many votes are up for grabs, but the two candidates will have a tough battle wooing middle-ground voters amid calls from activists for a boycott of the divisive vote.
Adding to the uncertainty, Hamdeen Sabahi called for a partial vote recount, citing violations that he claimed could change the outcome, a prospect that may further inflame an already explosive race.
Mr Sabahi, a socialist and a champion of the poor, came in third by a margin of 700,000 votes, leaving him out of the next round to be held on June 16 and 17.
Many Egyptians were dismayed by the early results, which opened a contest that looked like a throwback to Mubarak's era - a rivalry between a military-rooted strongman promising a firm hand to ensure stability and Islamists repressed under the old regime but now the most powerful political force in post-revolutionary Egypt.
Each candidate has diehard supporters but is also loathed by significant sectors of the population.
The first round race was tight. Preliminary counts from polling stations around the country reported by the state news agency gave Mr Morsi 25.3% and Mr Shafiq 24.9% with a less-than-100,000 vote difference. The election commission said about 50% of more than 50 million eligible voters turned out for the first round, which had 13 contenders.
A large chunk of the vote - more than 40% - went to candidates who were seen as more in the spirit of the uprising that toppled Mubarak, that is neither from the Brotherhood nor from the so-called "feloul", or "remnants" of the old autocratic regime.
Mr Sabahi came in third with a surprisingly strong showing of 21.5%.