The election represented Morgan Tsvangirai's third opportunity to dethrone Robert Mugabe.
Tsvangirai has spent the past 14 years building up his Movement for Democratic Change party to make it the only credible alternative to Mugabe's Zanu-PF. Even his closest supporters may believe a loss would mean he had been outmanoeuvred by Mugabe one too many times.
"This is a do-or-die election for him," said Eldred Masunungure, a political scientist at the University of Zimbabwe. "After being at the helm of the party since September 1999, if he loses, surely he must consider dropping the hat for someone else."
It has been a long journey for the 61-year-old to get this far. Born to a large family in grinding poverty in the eastern district of Buhera, he had to quit school early and go to work to help his siblings get an education.
After working for 10 years at Bindura Nickel Mine he became leader of the country's largest union, spearheading national strikes in the 1990s against Mugabe's economic policies.
Such actions pushed the teetotal, non-smoking Tsvangirai to political prominence.
Under Mugabe's rule, he was detained twice for his political activism and was twice cleared of treason charges.
Despite a strong following among urbanites and Zimbabweans in the rural west, Tsvangirai lost the race for the presidency in 2002 and 2008, despite running Mugabe close.
Five years ago he won 47.9 per cent of the vote to Mugabe's 43.2 per cent. In a fair race, he may well have won outright. But an orgy of violence against his allies forced Tsvangirai out of the hunt before the final round of voting.
For his troubles, he has been arrested repeatedly, charged with treason and faced four suspected assassination attempts. In 1997 assailants tried to throw him out his office window. His bodyguard has been killed and his wife died in a suspicious car crash that also put him in hospital.
But even among supporters, there is a lingering sense that Tsvangirai has repeatedly been outplayed by Mugabe, even when the international community forced the veteran leader to accept him as prime minister.
After more than four years of a forced unity government, Zimbabwe's most meaningful levers of power - from the security services to the judiciary - remain under Mugabe's control.
Despite this, he has managed to forge an alliance with Simba Makoni, a former finance minister and senior official of Mugabe's party, who came third in the first round of the 2008 elections.
While he is widely seen as a champion of democracy, recent scandals surrounding his love life, including a public divorce, have put a dent in his popularity.
He "gets distracted by a whole lot of things, including personal issues", said South African analyst Moeletsi Mbeki, who has known Tsvangirai a long time.