Burkina Faso beat Togo 1-0 thanks to an extra-time goal from Jonathan Pitroipa in Nelspruit after Nigeria's upset 2-1 win over the much-vaunted Ivorians in Rustenburg had thrown the tournament wide open.
Nigeria play Mali in the semi-finals in Durban on Wednesday and Ghana and Burkina Faso meet in Nelspruit the same day to determine the teams for next Sunday's final.
Nigeria were given just a 20 percent chance by their own coach Stephen Keshi of overcoming the Ivorians at the Royal Bafokeng Sports Palace.
But Sunday Mba's dramatic winner 12 minutes from time continued a nightmare sequence of tournaments for Didier Drogba and his Ivorian team mates who had been fancied to win the last five editions but came up short each time.
Mba, who plays his club football in the obscurity of the Nigerian league, weaved his way close to the edge of the Ivorian penalty area before hitting a shot that deflected off Souleman Bamba and looped over goalkeeper Boubacar Barry.
The goal ended the prospect of extra which both sides looked to have settled for.
Emmanuel Emenike gave Nigeria a deserved halftime lead with a rasping free kick that Barry failed to get close to.
The goal came two minutes from halftime and broke the deadlock in a game that quickly made clear Nigeria were to be no walkovers.
Although their coach insisted they were still in a side in transition with a longer term plan beyond this Nations Cup, Keshi had a clever game plan that kept Yaya Toure in check with John Obi Mikel and Lazio midfielder Ogenyi Onanzi sitting tightly on top of the African Footballer of the Year.
Without Toure given space to drive the side forward, the Ivorians showed little of the lustre evident in the earlier rounds.
"My boys showed character and this is the character I know that Nigeria have," Keshi told reporters.
There was a brief glimpse of the forceful potential of the Ivorians in full stride when they came out after halftime and swarmed all over Nigeria, equalising within five minutes through Cheick Tiote.
He stole in unmarked at the back post to head home Drogba's free kick but Drogba, Gervinho and Toure proved largely ineffective and the Ivory Coast meekly bowed out of the tournament.
Burkina Faso reached the semi-finals for only the second time when Pitroipa's swivelling header from Charles Kabore's corner in the 105th minute settled the match at the Mbombela Stadium.
"It's a dream come true, we were just happy to get to the last eight, that's a result for Burkina Faso," said coach Paul after a dour match.
"But I told my players we have a chance to go even further and qualify for the semis and I'm so happy they did it."
Sunday's wins followed success on Saturday for Ghana, who ended the fairytale run of the Cape Verde Islands, and Mali, who eliminated hosts South Africa in a penalty shootout.
- Sports & Recreation
- Burkina Faso
- Stephen Keshi
- Didier Drogba