But analysts say that Socialist former Trade Minister Igor Dodon's commanding lead in the first round leaves the second-place former education minister, Maia Sandu, with a huge amount of ground to make up before the November 13 second round.
With 99.5 percent of the ballots counted on October 31, Dodon was leading with 48.23 percent of the vote, just short of the outright majority needed to avoid a runoff.
Sandu, of the Party for Action and Solidarity, was in second place with 38.42 percent.
Dodon, who has questioned Moldova's reorientation toward the European Union since the Communists' grip on power was loosened in 2009, said early on October 31 that a second-round victory was "inevitable" and that "voters no longer believe" in the country's pro-EU government.
The 41-year-old economist says he wants to throw out Chisinau's 2014 EU Association Agreement and has hinted at joining the Moscow-led Eurasian Economic Union.
Turnout on October 30 was 49 percent of eligible voters, well above the required 33 percent.
Political analysts said that in order to stand a chance in the second-round vote, Sandu needs to encourage a higher turnout from young pro-EU voters who did not cast ballots on October 30.
Doru Petruti, director general of the Institute of Marketing and Polling in Chisinau, told RFE/RL that it will be "very complicated" and "difficult" for Sandu to close the 250,000-vote gap in a country with about 2.9 million eligible voters.
"She will have to ensure the support from all the other pro-European candidates, but first of all, she will have to persuade many center-right voters who don't necessarily like her to come out and vote for her in the second round," Petruti said.
Petruti said that voter turnout on November 13 would have to reach about 60 percent, with most of the extra votes going to Sandu, to give her a chance.
"Her chances were slim from the very beginning," Peruti added.
Sandu has said she thinks she can make up the difference with a strong turnout in the second round from younger voters.
"The young had a small turnout," Sandu, who warned before the vote of "risks of massive fraud."
Although Moldova's Communist Party leadership called for its members to boycott the October 30 vote, political analysts said it appeared that many of them turned out to vote for Dodon.
Meanwhile, Dodon is expected to gain backing on November 13 from many of the voters who supported the two other pro-Russian first-round candidates, Ciubasenco and Maia Laguta.
Ciubasenco, from Our Party, took third place with 6.03 percent of the first-round vote, while Laguta won 0.75 percent as an independent.
The five others competing in the first round, all pro-EU candidates, won a combined total of 6.65 percent.
They included former Prime Minister Iurie Leanca, of the Pro-European Coalition, with 3.11 percent; former interim President Mihai Ghimpu of the Liberal Party with 1.8 percent; and independent candidate and former parliamentary deputy Valeriu Ghiletchi with 1.08 percent.
Pro-EU candidate Silvia Radu won 0.4 percent, while Ana Gutu won 0.17 percent of the vote.