Dlamini Zuma, one of the longest serving Cabinet ministers since 1994, is up against Gabon's Jean Ping, who has occupied the all-important position of chairperson of the AUC since 2008.
The vote on Sunday is expected to be a bruising contest as the candidate must get a two-thirds majority to secure a win.
Ping is seeking a re-election and vowed in a statement this week that he would not back down, despite rumours he intended to withdraw from the contest. In January, Dlamini Zuma had sought to unseat Ping during a vote that ended in a stalemate.
This is a key position within the AU as it determines the effectiveness of the bloc and its ability to maintain stability in the continent -- something crucial for attracting foreign investment.
Since its inception in 2003, the AU has no doubt made remarkable strides towards the development of the continent. Observers say moving forward, the AU needs strong leadership at the top for it to continue building on the gains of the past decade, thus ensuring its continued existence.
If Dlamini Zuma is elected, it may not only be a boost for the continent, but will help South Africa gain more influence as it increasingly represents Africa on crucial powerful international fora like the G20, the UN Security Council and lately BRICS.
The continent is undergoing immense transformation, with talks of regional integration and intra-trade gaining momentum each day. With her experience in governance and supervision, many believe Dlamini Zuma may just be the right candidate the AU needs to get the job done.
The South African government this week reiterated its support for her candidature, expressing conviction that "she possesses both the capacity and the will to help the continent in its endeavors to create a better life for all Africans".
Despite the underlying complex political calculus that has tended to characterise African politics, commentators say Dlamini Zuma, buoyed by the unequivocal support of SADC, could emerge victorious come 15 July.
Add to this the AU policy of alternating senior positions between men and women. South Africa has argued that this policy has not been enforced in a position of the chair of the commission.
International Relations and Cooperation Minister Maite Nkoana Mashabane recently told her SADC counterparts that the region was in position to field a formidable candidate that met the requirement.
On Thursday, chairperson of the Executive Council of the AU Nassiru Bako Arifari urged the union's leadership to ensure that the issue of leadership was "put to rest", adding that a leaderless AU Commission risked undermining the credibility of continent.
"Our continent is faced with serious conflicts that need our attention and effectiveness of the union and the past six months had not been easy... In the face of all of this, we have a responsibility to maintain peace and stability on the continent," Arifari said.
Opening the Executive Council meeting, which is attended by foreign ministers across the AU member states, Arifari said the AU remained concerned about the unresolved political situation in Mali, Somalia, Western Sahara and the latest developments between Sudan and South Sudan.
"The union is determined to solve the Malian crisis and the situation is Sudan and South Sudan and in the face of all we shall remain focus to offer solutions to these crises," said Arifari.
South Sudan, which ironically celebrated its 1st anniversary as an independent state last week, has been at loggerheads with its neighbour Sudan over oil reserves. The second round of the AU-led negotiations between the two countries was adjourned on June 28 after a week of talks in Addis Ababa.
