Zanu-PF's national chairperson, Ambassador Simon Khaya Moyo, who doubles as the party's head of the electorate, told the Mail & Guardian on Thursday that while he's bound by law not to reveal the results, he was confident Zanu-PF would emerge victorious.
"From what we hear and from what we see outside polling stations there's no doubt that we are doing very well," Moyo said. "It's definitely a victory for us."
Moyo, who once served as Zimbabwe's ambassador to South Africa, commended his country's voters for a generally peaceful election.
"Going by these [preliminary] results, people appreciate the policies of my party and as a chairperson of Zanu-PF I'm very elated," he said.
MDC-T officials, who had believed the party would win the polls or at least run a close contest, were in a state of shock, claiming Zanu-PF had won the polls through fraud.
MDC-T leader Morgan Tsvangirai told journalists the election was a "huge farce" before adding the results were "null and void".
"Our conclusion is that this has been a huge farce. The credibility of this election has been marred by administrative and legal violations which affected the legitimacy of its outcome. It's a sham election that does not reflect the will of the people," he said.
Former deputy minister Obert Gutu, who was Tsvangirai's election agent in Harare, said the results were a joke.
"It's the same as saying Usain Bolt lost a 100m race against a blind person, who has never raced," he said.
The government expressed determination to implement an aspect of the Electoral Act making it a criminal offence to release results before the country's electoral commission makes an official announcement.
Counting began on Wednesday night as soon as some polling stations were closed. Unlike South Africa's Independent Electoral Commission (IEC), where journalists can report from provisional results displayed on screens at the elections centre, the Zimbabwe Electoral Commission (ZEC) wait for all results from wards, provinces and national ones to be counted before making an announcement.
Releasing unofficial results in Zimbabwe can land one in jail and police have made it clear they are ready to act on any premature claims about the results.
Police spokesperson Charity Charamba warned that "all people who may wish to announce the results of elections before ZEC does so, risk being arrested". This also applies to online publications.
This same warning was on Sunday directed to Tsvangirai, with his fellow candidate Robert Mugabe threatening to arrest him should he attempt to declare victory before results were announced.
In 2008, it took ZEC weeks to announce the election outcome, a situation that saw both Mugabe and Tsvangirai claiming early victory.
Zimbabwe's Electoral Act states that the ZEC is obliged to declare presidential election results not more than five days after the day of voting. It's expected that Zimbabweans will know by Monday who will lead the country for the next five years.
Zanu-PF officials were celebrating after information filtered through that they had taken all House of Assembly seats in their Mashonaland Central stronghold and won resoundingly in Mashonaland East and Mashonaland West provinces, where there were huge turn-outs.
Zanu-PF also had a huge majority in Manicaland and Masvingo provinces which were previously dominated by the MDC-T.
In Harare, sources from ZEC and contesting parties said Zanu-PF had won seven of the 29 seats, after winning one in the 2008 elections.
Zanu-PF also had a majority in Matabeleland South and took a number of seats in Matabeleland North.
MDC-T however won all seats in Bulawayo while Welshman Ncube's MDC-T failed to claim a single seat.