Zimbabweans face third Mugabe-Tsvangirai showdown HARARE (Reuters) - Zimbabweans voted on Wednesday in a fiercely contested election pitting President Robert Mugabe against Prime Minister Morgan Tsvangirai, who has vowed to push Africa's oldest leader into retirement after 33 years in power. With no reliable opinion polls, it is hard to say whether the 61-year-old Tsvangirai will succeed in his third attempt to unseat the 89-year-old Mugabe, who has run the southern African nation since independence from Britain in 1980. Both sides are forecasting landslide wins but, in a country with a history of election violence, the bigger question is whether the loser will accept the result of a poll dogged by logistical problems and allegations of vote-rigging. Polls opened on time at 0500 GMT (1 a.m. ET) across the country, with long queues of people braving a bout of unseasonably cold weather to stand in line from well before dawn. In one polling station in the western province of Manicaland, a key swing region, the queue stretched for a kilometer (0.6 miles). "I got up at 4 but still couldn't get the first position in the line," said sawmill worker Clifford Chasakara. My fingers are numb, but I'm sure I can mark the ballot all the same. I'm determined to vote and have my vote counted. In Harare, the epicenter of Tsvangirai support, the mood was excited and upbeat. "We are here to vote and I'm convinced Harare will lead the way to change," John Phiri, a domestic worker in his 30s, told Reuters in a polling station in the upmarket Mount Pleasant suburb. Asked on the eve of the vote if he and his ZANU-PF party would accept defeat, Mugabe was unequivocal: "If you go into a process and join a competition where there are only two outcomes, win or lose, you can't be both. A spokesman for Tsvangirai's Movement for Democratic Change (MDC) said the party was prepared only to accept the results if the poll was "free and fair." Mugabe's words were in marked contrast to the thrust of what he described as an "energy-sapping" campaign, and may ease fears of a repeat of the violence that broke out after he lost the first round of an election in 2008. Around 200 Tsvangirai supporters were killed in the unrest before South Africa brokered a power-sharing deal that stopped the bloodshed and stabilized the economy, but established a government characterized as fractious and dysfunctional. Western election observers have been barred from the elections, leaving the task of independent oversight to 500 regional and 7,000 domestic monitors. Results are expected well within the five-day legal limit. Around 6.4 million people, or half the population, are registered to vote. The verdict of observers is crucial to the future of Zimbabwe's economy, which is still struggling with the aftermath of a decade-long slump and hyperinflation that ended in 2009 when the worthless Zimbabwe dollar was scrapped. Despite this, Tsvangirai urged African monitors not to give the vote the thumbs-up simply because they do not witness bloodshed. He is fixing this election in a more sophisticated fashion than previous ZANU-PF campaigns of beatings, killings and intimidation," he wrote in an editorial in the Washington Post. Additional reporting by Nelson Banya; Writing by Ed Cropley; Editing by Catherine Evans