TEHRAN, Young Journalists Club (YJC) - It was his first public speech since Mugabe fired him on November 6 over a succession tussle with the former first lady, a move that prompted the military's intervention to force Mugabe from power, leading to his resignation on Tuesday.
Mnangagwa, who has close ties to the army and the security establishment, will be sworn in as president at an inauguration ceremony on Friday, officials said.
"Today we are witnessing the beginning of a new and unfolding full democracy in our country," he said in front of hundreds of supporters, some wearing shirts emblazoned with images of the 75-year-old leader.
"We want to grow our economy, we want jobs... all patriotic Zimbabweans (should) come together, work together," he said.
He was surrounded by a large security detail and arrived at the headquarters of the ruling ZANU-PF party in a presidential-style motorcade.
He had flown in earlier to Harare's Manyame airbase from South Africa, and met key ZANU-PF officials before heading to the State House, the nerve centre of Zimbabwe's political establishment, for a briefing.
"Great speech all round, can't describe how I felt seeing him after what he went through. All I want is job creation," said Remigio Mutero, 30, an unemployed IT graduate.
Mugabe's iron grip ended Tuesday in a shock announcement to parliament, where MPs had convened to impeach the 93-year-old leader who dominated every aspect of Zimbabwean public life for decades.
He had last been seen in public on Friday and had given a televised address on Sunday, but neither he nor his wife Grace have been seen since, with their whereabouts unknown.