The talks came as the UN Security Council prepared to discuss possible sanctions against Zimbabwe over the presidential run-off which was marred by allegations of violence and vote-rigging.
Tsvangirai pulled out of the June 27 poll just days before it took place and Robert Mugabe, Zimbabwe's leader for 28 years, claimed victory.
There was little information about what was discussed and who took part, but Al Jazeera's Kalay Maistry, reporting from Johannesburg, said that the MDC's number two could have left Zimbabwe, where he has been charged with treason, to go to the talks.
"We did see yesterday from Zimbabwe that the MDC's Tendai Biti has asked a court to return his passport so he could attend talks in South Africa - but there is still no indication that such high level of members of the various parties are meeting."
Patrick Chinamasa, the justice minister, and Nicholas Goche, the labour minister, were representing Mugabe's Zanu-PF, sources said.
Representatives of the breakaway opposition faction of Arthur Mutambara, who met Mugabe last Saturday, also reportedly attended the talks.
G8 leaders meeting in Japan this week called for a special envoy to assist in mediation efforts, while also rejecting the legitimacy of Mugabe's government and threatening further sanctions against his regime.
A draft resolution authored by the US calls for a freeze on assets and a travel ban for Mugabe and 13 close associates, as well as an arms embargo.
It would also demand that the Harare government "begin without delay a substantive dialogue between the parties with the aim of arriving at a peaceful solution that reflects the will of the Zimbabwean people as expressed by the March 29 [first-round presidential] elections."
Tsvangirai finished ahead of Mugabe in that election but did not gain the outright majority needed to avoid a run-off.
A number of African governments, including South Africa, have rejected the push for further sanctions, saying it will only worsen the situation.
However, Liberia said on Thursday that sanctions would send a "strong message" to Mugabe.
"I think it [sanctions] is fine to bring about satisfactory resolution," Ellen Johnson-Sirleaf, the president, said.
Her statement came as she arrived in South Africa to deliver the Nelson Mandela Annual Lecture as part of events to mark the former South African president's 90th birthday.
Johnson-Sirleaf also expressed support for moves to appoint a special envoy to assist in Zimbabwe mediation efforts.