His two biggest rivals -- popular Dakar ex-mayor Khalifa Sall and Karim Wade, the son of the previous president -- were disqualified after being convicted of corruption in trials questioned by rights groups.
"Victory in the first round is indisputable," a Macky Sall told a recent Dakar campaign rally.
Sall faces competition from four opposition rivals -- lesser-known perhaps, but campaigning hard against the president's plans for a second phase in a controversial infrastructure project called "Emerging Senegal."
The giant scheme is Sall's legacy, but critics deride it as a waste of taxpayers' money, out of touch with needs -- and a potential debt dinosaur if much-promised investment fails to emerge.
"If I am elected, I will throw his Senegal debt plan in the trash," one of Sall's election challengers, tax inspector-turned MP Ousman Sonko, has vowed.
Sall's other three rivals are former prime minister Idrissa Seck, Issa Sall of the Unity and Assembly Party (PUR), and former justice and foreign minister Madicke Niang.
The president is not related to either Khalifa or Issa Sall.
The five-horse race leaves voters with a limited choice compared to 2012, when 14 candidates vied for the top post, and 2007, when 15 battled it out.
STABILITY ABOVE ALL
A new system approved by parliament last year despite opposition party resistance, requires candidates to demonstrate they have the support of a minimum number of citizens and regions.
Once the new regulations were applied, only seven candidates made the cut, two of whom were then disqualified.
"I can't be bothered to deal with politics," said shopkeeper Astou Fall of Bambey, in central west Senegal.
"May the best win and peace continue, we value our national stability," he said, reflecting a commonly-voiced sentiment.
Both Khalifa Sall and Karim Wade -- his SDP party's only presidential candidate -- have claimed their criminal convictions were engineered to rule them out of the race.
Supporters of the convicted men have staged demonstrations to call for free and fair elections, while rights group Amnesty International last year spotlighted "unfair trials" in Senegal, and a "lack of independence" by the judiciary in Khalifa Sall's case.
Senegal, which has known two peaceful power transfers, in 2000 and 2012, and no coup d'etat, is held up by some as a model of stability in West Africa.
But election campaigns are typically marred by accusations of corruption, disinformation and sometimes violence.
Just last week, clashes between supporters of rival parties left two dead at Tambacounda, about 420 kilometres (261 miles) east of Dakar.
Ex-president Wade has called for the burning of election materials and attacks on voting stations, prompting the government to denounce an "attitude of subversion".
The country, with a 90-percent Muslim population, is reputed for religious tolerance, and has been spared the jihadist attacks plaguing other countries in the region.
But it has been reinforcing security and laws, sometimes at the cost of freedom, according to rights organisations.
Opposition rallies have recently been banned and pre-trial detention for people suspected of "terrorism" extended from 48 hours to 12 days.
Some 6.7 million people in a population of around 16 million are registered to vote.
Preliminary results are expected soon after polling closes at 1800 GMT on Sunday, but will only become official a day or two later.
A candidate must get more than 50 percent of the votes cast to prevent a second-round runoff.
If no-one garners more than half the votes on Sunday, March 24 is the provisional date for a second voting round, though the exact timing will be determined by how long it takes to officially proclaim the results from the first round, and whether these are then challenged.