More than 25 million citizens of the Democratic Republic of the Congo (DRC) were registered to vote between incumbent President Joseph Kabila, who took a lead in July's first round, and Jean-Pierre Bemba, a businessman and former rebel who became a vice-president during a three-year transition from war to peace.
In the capital Kinshasa, where European Union troops helped police the process, the start of voting saw torrential rain, while elsewhere at least one person was killed in polling violence.
Election officials and observers were manning 50,045 polling stations across the country; they closed earlier in the east, an hour earlier than the scheduled shutdown at 5:00 pm (1600 GMT) in the west, including Kinshasa.
Although counting was to start immediately, provisional results were not expected on November 19, while those from the provincial parliamentary polls are due in December.
More than 1,000 international and 40,000 Congolese observers were monitoring the polls, while some 80,000 policemen, 17,600 United Nations troops and 1,200 EU soldiers were helping with security.
People were also voting for members of provincial legislatures, where they had a choice among 13,476 candidates for 632 seats, but it was the leadership race they talked about -- the first real chance to choose their own national leader in 40 years.
"Since I was born, I've never been able to choose my own president," said
Lionel, an unemployed 36-year-old voter in Kinshasa's Bandalungwa district, adding that he hoped the elections would be fair "so the loser will be able to accept his defeat."
About 1,300 kilometres away, in Goma on the Rwandan border,
Esther Kavumba recalled, at 75, how in the days of longtime dictator Mobutu
Sese Seko, "there were always soldiers here to force us to vote for Mobutu.
"Now we do it alone," she said with relief.
The Mobutu regime, ousted in 1997 by Kabila's late father, was infamous for plundering the vast mineral resources of the country, which was then called Zaire.
The regime's downfall was followed by a 1998-2003 war when Rwandan-backed rebels and Bemba's forces battled the government in Kinshasa, with foreign African armies intervening on both sides.
Fears of violence ran high after a rocky pre-electoral campaign studded with almost daily clashes in the provinces and after fighting in Kinshasa in August between the presidential guard and Bemba's militia, which claimed at least 23 lives.
However there were no reports of serious incidents except at some towns in northern Equateur province, where UN and voting officials reported one person killed and somebody wounded in Bumba, a border town on the Congo River.
"The situation has returned to calm and voting operations are taking place normally throughout Equateur," Suzanna Gouveira, the information chief in the province for the UN mission in DRC (MONUC), told AFP from Equateur's chief town, Mbandaka.
Announcing the casualties, police said the violence erupted when a polling station chief was caught stuffing a ballot box on Kabila's behalf and angry
Bemba supporters retaliated, leading to clashes with police.
An electoral official reported an attack on a pro-Kabila radio station and an assault on a polling station where ballot boxes were seized in Equateur, a
Bemba stronghold.