At stake is the potential end of an administration that has pushed investor-friendly policies but failed to ease economic hardship in one of coup-prone West Africa's more stable democracies.

Voters had a choice of 19 contenders to replace President Macky Sall, stepping down after a second term marred by unrest over the prosecution of firebrand opposition leader Ousmane Sonko and concerns that Sall wanted to extend his mandate past the constitutional limit.