CARACAS Venezuelans voted on Sunday on whether to honour Hugo Chavez's dying wish for a longtime loyalist to continue his self-styled socialist revolution or hand power to a young challenger promising business-friendly changes.
Acting President Nicolas Maduro led opposition rival Henrique Capriles in most polls heading into the vote, buoyed by Chavez's public blessing before he died from cancer last month.
Maduro supporters mobilized voters with pre-dawn bugle calls in the rough barrios of Caracas, where Chavez is revered as a hero of the poor.
Lines formed under blistering sunshine at some voting centres, but many were shorter than they were at last October's election, when an ailing Chavez beat Capriles. Then, a record 80 percent of registered voters cast ballots following an aggressive get-out-the-vote campaign by the Chavista camp.
"We're going to elect Maduro president because he's following the path set by Chavez," Morelia Roa, a 58-year-old nurse, said after casting her ballot in the same working class Caracas district where Maduro voted.
Maduro, a 50-year-old former bus driver, has promised to deepen Chavez's "21st century socialism" if he triumphs. Capriles, an athletic 40-year-old who has generated widespread enthusiasm among the opposition, wants to take Venezuela down a more centrist path.
Whoever wins will inherit control of the world's biggest oil reserves in an OPEC nation, where stark political polarization is one of Chavez's many legacies. Also at stake is the generous economic aid Chavez showered on left-leaning Latin American governments from Cuba to Bolivia.
Following opposition complaints that some people were illegally helping elderly voters cast their ballots, Capriles urged his followers to report any violations of election laws.
But he also stressed he would respect the outcome of the vote, whatever it might be.
"Today, all Venezuelans are reporters. If you see something irregular, take a picture, air it on social media," Capriles said after voting. "But let there be no doubt, we will respect the will of the people."
Electoral authorities said voting was going smoothly and that there was no evidence of irregularities. Given the deep mutual mistrust on both sides, some worry that a close or contested result could spark unrest.
Some 170 international observers were on hand, many from left-leaning political parties across Latin America.
Polls were due to close at 6 p.m. (6:30 p.m. ET/2230 GMT), but voting continued past that in some places to accommodate queues.
Sunday's vote was the first presidential election in two decades without Chavez on the ballot. In many ways, though, it is all about the late president, who was viewed by the poor as a messiah for giving them a political voice and for funnelling billions of dollars of oil revenue into social programs.
Maduro campaigned as a loyal disciple of Chavez, repeatedly calling himself an "apostle" and "son" of the late president. Chavez gave Maduro a huge boost by publicly endorsing him in his final speech in December before heading to Cuba for his last cancer operation.
True to form, Maduro dedicated his vote on Sunday to his political mentor.
"The last 21 years of my life have revolved around the dreams of a man, of a giant," an emotional Maduro said. "I never thought I'd be here. But here I am ... And I'm going to be president of the republic for the next six years."
If Maduro wins, he will immediately face big challenges as he tries to stamp his authority on a disparate ruling coalition while lacking his mentor's charisma, or the healthy state finances that Chavez enjoyed in last year's race.
It is hard to predict how he might do things his own way. Like many senior officials, Maduro was passionately loyal to Chavez and never voiced a different opinion in public.
Supporters say he could use his background as a union negotiator-turned-diplomat to build bridges, perhaps even with the United States after tensions during Chavez's 14-year rule.
But there was little sign of his softer side on the campaign trail. Maduro's rhetoric veered from outraged - alleging opposition plots to kill him using mercenaries - to light-hearted, such as poking fun at his often-cited tale of how he was visited by Chavez's spirit in the form of a bird.
More often he sounded indignant, accusing the "far right" of plotting a repeat of a short-lived coup against Chavez a decade ago if the opposition loses Sunday's vote.
Maduro's camp said his Twitter account was hacked during the day, as well as those of other senior Socialist Party members, with obscene messages posted on them.
Should he pull of an upset, Capriles will also have a tough time running Venezuela. One of the biggest challenges will be to win over suspicious supporters of Chavez and Maduro. Both repeatedly derided the opposition candidate as a pampered rich kid, traitor, and puppet of "U.S. imperialism."
In last year's campaign, Capriles carefully avoided disparaging Chavez, in a bid to woo the poor. He has not afforded Maduro the same respect, denouncing him and his "coterie" as phony socialists who have enriched themselves while paying only lip service to Chavez's deeply held ideology.
Capriles touts a Brazilian-style model that mixes pro-business policies with heavy state spending on the poor, a recipe that made Brazil one of the world's hottest emerging economies in the past decade.
The opposition hopes bubbling discontent over daily problems such as rampant crime, high inflation, chronic power outages and occasional shortages of food staples and medicines will tip the vote in favour of Capriles.
"Capriles is our only hope. He's the best leader the opposition has had and could be a great president," Alberto Gomez, a 55-year-old bakery owner, said after voting in an upscale district of Caracas.
"The country is a mess," he added. "It's time to forget Chavez and create a new Venezuela outside of his shadow."
(Additional reporting by Deisy Buitrago and Andrew Cawthorne; Editing by Kieran Murray, Jackie Frank and David Brunnstrom)