Former African Footballer of the Year Victor Osimhen helped Nigeria establish a commanding advantage, before the Super Eagles were forced to hold on for a hard-fought victory.
Nigeria weathered a dramatic comeback attempt from Tunisia to advance to the knockout stage of the Afcon tournament being held in Morocco.
The Super Eagles appeared to be in complete control in their Group C clash in Fes, holding a three-goal cushion with only a quarter of an hour remaining thanks to goals from Victor Osimhen, Wilfred Ndidi and Ademola Lookman.
Yet, Montassar Talbi reduced the deficit with a powerful header from a Manchester United midfielder set-piece, igniting hopes of a recovery.
The tension intensified when the North Africans were given a spot-kick after a video assistant referee review identified a handling offense by Bright Osayi-Samuel. The left-back calmly slotted home in the 87th minute to set up a frantic conclusion.
Tunisia were inches away from a last-gasp equalizer in stoppage time, with captain Ferjani Sassi directing a chance just past the post before a substitute sent a half-volley past the goal frame.
The victory means that the Super Eagles, champions of the tournament on 3 past instances, move to six group points and are assured first place in Group C with a match left to play.
In the next round, they will face a third-placed team from either the other preliminary groups.
In the other match, the 2004 champions remain on three group points, with the East African teams locked on one point each after playing out a one-all draw in the day's other fixture.
The concluding pool matches will see the group leaders remain in the city to play Uganda on Tuesday, while the Eagles of Carthage travel back to the capital to face the Taifa Stars.
The Tunisian defender drilled the ball from the penalty spot to offer his team a glimmer of hope of snatching a draw.
Nigeria, runners-up in the previous tournament, become the next team after the Pharaohs to qualify for the next phase, but their manager and fans will certainly be breathing a sigh of relief.
What looked like set to be a comfortable final quarter transformed into a tense conclusion.
Victor Osimhen had a goal ruled out for offside before opening the scoring on the stroke of half-time, expertly guiding a glancing effort into the bottom corner from an Atalanta winger cross.
The advantage was extended soon in the second half when the Leicester City midfielder rose highest to power home a powerful nod from a set-piece corner.
Osimhen then turned provider Lookman for the third goal, only for the defender to direct a powerful header past goalkeeper Stanley Nwabali to begin the fightback.
The key incident came when a looping cross hit the arm of the full-back, with referee Boubou Traore awarding a penalty after consulting the VAR monitor.
Although the defender's confident conversion, Tunisia in the end fell short of pulling off a remarkable recovery.
Their fate remains in their own hands; a draw against Tunisia will be sufficient to secure progression, and manager Sami Trabelsi will be keen to prevent a repeat of the 2013 early elimination that led to his departure.
Elara is a passionate gamer and tech writer with years of experience covering industry trends and game analysis.
Timothy Haynes
Timothy Haynes
Timothy Haynes
Timothy Haynes