Election: single candidate and two or more candidates
Section 179(4) · 1999 Constitution (2004 edition)
What Constitution says
(4) In default of a candidate duly elected under subsection (2) of this section, the Independent National Electoral Commission shall within seven days of the result of the election held under that subsection, arrange for an election between the two candidates and a candidate at such election shall be deemed to have been duly elected to the office of Governor of a State if - (a) he has a majority of the votes cast at the election; and (b) he has not less than one-quarter of the votes cast at the election in each of at least two- thirds of all the local government areas in the State.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 83–84. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections