HARARE-- Zimbabwe's Constitutional Court confirmed President Emmerson Mnangagwa's disputed July 30 election victory on Friday, dismissing an opposition challenge that had held up his inauguration, which will now be held on Sunday.

Before the vote, Mnangagwa had said a credible election could pull Zimbabwe out of its diplomatic isolation under former President Robert Mugabe, ending international sanctions and prompting an economic recovery.

Instead, the vote left the nation polarized, with Nelson Chamisa, who leads the opposition Movement for Democratic Change (MDC), mounting the legal challenge and violence flaring on the streets of Harare.

In a unanimous ruling of the nine judges of the country's top court, Chief Justice Luke Malaba said Chamisa had failed to prove allegations of fraud during the presidential vote.

"Emmerson Dambudzo Mnangagwa is duly declared the winner of the presidential elections held on the 30th of July 2018," Malaba said in his ruling.

Chamisa had earlier said he reserved the right to take alternative actions, including peaceful protests, if he lost the legal case.

On Friday, he did not spell out his next step but told his supporters on Twitter that he would consult them on the "course of action to be taken to rescue our beautiful Zimbabwe from the jaws of poverty, corruption and dishonesty."

The election, in which Mnangagwa and Chamisa were the main contenders, was touted as a crucial step toward shedding Zimbabwe's pariah reputation and securing international donor funding to revive an economy suffering chronic shortages of investment and cash, as well as high unemployment.

An army crackdown in response to post-election violence by opposition supporters left six people dead on Aug 1, recalling the heavy-handed security tactics that marked the 37-year rule of Mugabe, who was removed from power in November 2017.

Mnangagwa now faces the challenge of persuading the international community that the army crackdown and lapses in the election process will not derail his promise of reforms to overcome corruption and mismanagement under Mugabe.

After the ruling was delivered, the president called for peace on his Twitter feed: "Nelson Chamisa, my door is open and my arms are outstretched, we are one nation, and we must put our nation first. Let us all now put our differences behind us," he said.