Goals from Emmanuel Emenike and Mba secured a famous win for the Super Eagles in Rustenburg despite Newcastle midfielder Cheick Tiote netting for the fancied Ivoirians.
Nigeria had the game’s first chance after eight minutes when Chelsea winger Victor Moses whipped in a dangerous set-piece cross which Ideye Brown headed over.
Moses threatened himself soon after when his rasping shot from 25 yards stung the palms of Ivory Coast goalkeeper Boubacar Barry, who parried to safety.
Spartak Moscow forward Emenike missed a golden chance for the Super Eagles on 27 minutes, firing high and wide when well-placed.
Nigeria took a deserved lead just before half-time when Emenike smashed a dipping, swerving shot from a short free-kick past Barry, who should have done better.
Tiote levelled for the Elephants just after the break with a back-post header from Didier Drogba’s free-kick, his first international goal.
And Brown missed a great chance for Nigeria on 64 minutes when rose unchallenged to head Moses’ corner, but his effort was straight at Barry.
Manchester City midfielder Yaya Toure drew an outstanding save from Nigeria goalkeeper Vincent Enyeama soon afterwards with a low drive that was well turned away.
And the Super Eagles seized the lead with 12 minutes to go when Mba’s shot from the edge of the box, after a wonderful run, deflected in off Sol Bamba.
Chelsea midfielder John Obi Mikel produced a crucial tackle in the box with five minutes to go, taking the ball away from Ivory Coast substitute Lacina Traore, who had the goal at his mercy.
Nigeria – looking for their first Africa Cup of Nations title since 1994 – now move on to face Mali in the semi-finals on Wednesday in Durban.
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