When final results were finally announced on 10 November, Yushchenko -- with 39.9 percent of the vote -- was fractionally ahead of Prime Minister Yanukovych, who garnered 39.3 percent.
Many predict the runoff will be equally close, including incumbent Ukrainian President Leonid Kuchma, who nominated Yanukovych as the government's candidate: "As to who will win, well, you know, I can't, as you can understand, reply to such a question because the winner ought to be Ukraine. But anybody can win in this situation. I can only say that there won't be a big percentage difference [between the two candidates]."
Russian President Vladimir Putin, who endorsed Yanukovych's policies during a visit to Ukraine in October, arrived in the country again today for a two-day visit. Putin and Kuchma are due to meet first in the southern Russian port of Kavkaz before traveling to Ukraine's Crimea peninsula.
Opinion polls ahead of the second-round vote vary widely. One survey gives Yanukovych 42 percent support, compared to 38 percent for Yushchenko. Another predicts victory for Yushchenko with 47 percent of the vote, compared to 40 percent for the prime minister.
Most of the other candidates gained negligible shares of the first-round vote, save for Socialist leader Oleksander Moroz, who gained almost 6 percent, and Communist leader Petro Symonenko, with 5 percent.
The Socialists have now opted to back Yushchenko -- the most important alliance made so far in the realignment process after the first round.
Socialist deputy Yosip Vinskyy said his party's extensive nationwide infrastructure, which helped Moroz in the first round, will now be put to work for Yushchenko: "The fundamental reason why we supported Yushchenko is [because] we could never, under any circumstances, support Yanukovych. Our party, which from 1993 has been in opposition, which suffered massive persecution, was the victim of [government] brutality in 1999 when we effectively stood alone against this government, which took part in protests in 2000 under the slogan 'Ukraine Without Kuchma,' could not support or facilitate a candidate who wants to [prolong those policies]."
In return for their support, the Socialists are demanding constitutional reforms transferring much of the president's powers to parliament, the withdrawal of Ukrainian troops from Iraq; and that Kuchma not be given immunity from possible prosecution.
Another candidate from the first round, Anatoliy Kinakh, who gained about 1 percent of the vote, has also pledged the support of his powerful Union of Industrialists to Yushchenko. But some local branches of the party say they will support Yanukovych.
A number of other parties have split, including the National Democratic Party and the Center Party, with some of their deputies in parliament siding with Yushchenko, while others say they are undecided or that they will back Yanukovych.
A volunteer organization that had campaigned for Kyiv Mayor Oleksandr Omelchenko has declared that it will now work for Yushchenko. However, Omelchenko himself, who received less than half a percent of the vote, has not endorsed the opposition candidate.
Almost immediately after the first round, Yanukovych received the backing of the leader of the Progressive Socialists, Natalya Vitrenko, who received around 1 percent of the vote.
The Communist Party is most significant group that has not yet officially thrown its weight behind a candidate. Its chief, Petro Symonenko, said he does not back either man. But Russian Communist Party chief Gennadii Zyuganov -- whose lead Symonenko usually follows -- earlier this week urged Ukrainian communists to vote for Yanukovych.
A televised debate on 15 November is expected to heavily influence undecided political groups and voters. Yushchenko has been keen to face his rival in such a forum because of the nationwide access to voters it provides. The opposition's biggest complaint has been that it has either been excluded from or has been given negative coverage by most of Ukraine's mass media, which is either directly or indirectly controlled by the government.
Yanukovych has shied away from confronting his rival on television and is not considered to be a strong public performer. Yanukovych's campaign manager, Serhiy Tyhypko, had previously said Yanukovych would take part in a debate only if Yushchenko apologized for repeatedly referring to the government as "bandits."
"Neither Viktor Yanukovych nor his campaign staff ever made any statements about refusing to take part in [televised] debates. We want to take part in these debates, but we want fairness reinstated before that and for Viktor Yushchenko to apologize to Viktor Yanukovych about the insults he made -- personal insults."
Yushchenko has refused to apologize. Yanukovych said he has agreed to debate due to the many letters from supporters urging him to do so.