Just a year ago Zimbabweans were certain that this election - like others before it - would return Robert Mugabe and his clan of cronies to power. This was a country in which hope had been smothered.

This morning, from long before sunrise, Zimbabweans queued to vote knowing that there was at least the possibility of a decisive break with the past. Gone was Mugabe.

And the man who ousted him last November, Emmerson Mnangagwa, was facing a strong challenge from a politician 35 years his junior.

Whether Mnangagwa or his main opponent Nelson Chamisa wins, the fear that characterised the Mugabe years is ebbing away.

In Chitungwiza, a satellite town of Harare, I met a returned political exile, now election observer, Tafadzwa Musekiwa.

As we watched the patient crowds queue to vote he spoke: "This is what it should have been like always."

There is a great sense here of lost potential.

But Zimbabwe has re-engaged with the world. Both incumbent and challenger recognise that without foreign investment and aid the country is doomed to claustrophobic stagnation.

The world will need to be satisfied that the poll has been free and fair if investment is to flow. It won't happen if the results are disputed and Zimbabwe is pitched into turmoil.