Tsvangirai said "negotiations have been adjourned until tomorrow" as he left the talks, adding: "We will advise on progress later."
The opposition leader believes his victory in the first round in March gives him the right to the most powerful positions.
Mugabe 'seeking immunity'
But Mugabe's Zanu-PF party has insisted he must be recognised as president in any deal as he won the run-off vote in June.
The 14-hours of negotiations on Monday reportedly included proposals for Mugabe, who has ruled since independence from Britain in1980, to take on a more ceremonial role in exchange for amnesty from prosecution, with Tsvangirai being made executive prime minister.
Power-sharing talks began after the political rivals signed a deal on July 21 laying the framework for negotiations.
In a sign the two sides were moving closer to an agreement, the parties issued a joint statement earlier this week calling on their supporters to halt political violence.