Recalled Stephane Mbia scored twice as Cameroon edged Tunisia 3-2 after extra time in an African Nations Cup quarter-final thriller here on Monday.
Dropped following a 4-2 loss to Egypt in their first group match, Mbia made the most of his second chance to open the scoring in the first half and snatch the winner two minutes into extra time.
Cameroon now tackle hosts Ghana on Thursday in an Accra clash of countries who have won the biennial tournament four times each while Ivory Coast meet title holders Egypt in Kumasi later that day in a repeat of the 2006 final.
It was a cruel result for Tunisia, who overcame a two-goal deficit and appeared the stronger side entering the 30 additional minutes in the first match of this tournament to require extra time.
Tunisia coach Roger Lemerre took his rotation policy to a new level by making seven changes from the team that held Angola goalless to top their group and remain in this northern town for one more game.
Among those recalled was veteran Brazil-born striker Francileudo dos Santos, the leading all-time Tunisia scorer with 21 goals, with teenage wonder boy Amine Chermiti relegated to the bench.
Cameroon coach Otto Pfister was also in mood for change with three new faces from the team that put three goals past Sudan without reply here, including the elevation of striker Mohamadou Idrissou ahead of Joseph-Desire Job.
Tradition slightly favoured the 'Indomitable Lions' as they drew with the 'Carthage Eagles' in 1982 and triumphed 3-0 in a semi-final eight years ago with Rigobert Song, Geremi Njitap and Samuel Eto'o survivors of that side.
Eto'o set the crowd alight even before the kickoff as a defeaning roar greeted his picture on the giant screen during the playing of the national anthems.
The first chance fell to Jean Makoun of Cameroon after five minutes with the pint-size midfielder climbing to head a deep cross wide as his side set the pace.
Yassine Chikhaoui, a Switzerland-based striker who has grown in stature as this tournament progresses, brought a fine save from Carlos Kameni at the other end in a fast, physical opening spell.
This was not a match for the faint hearted and it came as no surprise when the Malian referee finally raised his yellow card on 14 minutes when Mehdi Nafti cynically fouled Achille Emana.
Another four minutes and Cameroon were ahead as Timothee Atouba set up Alexandre Song for a cross that evaded goalkeeper Hamdi Kasraoui and two defenders and Mbia raced in at the far post to push the ball over the line.
Cameroon struck again nine minutes later as a trademark Geremi free kick floated over the wall and Kasraoui and landed in the left corner of the net.
With 34 minutes gone Tunisia were back in contention from an equally brilliant set piece as Chaouki Ben Saada claimed his second goal of the tournament with a free kick that flew over Kameni into the near corner.
Karim Hagui, the Tunisian 'minder' of Eto'o, retired with a hip injury to be replaced by Sabeur Ben Frej, Dos Santos rattled the crossbar, and Kameni did superbly to stop the rebound shot from Saada as a scintillating half ended.
While Tunisia showed more urgency as the second half progressed, leading all-time Nations Cup scorer Eto'o remained a threat and it took three opponents to prevent him shooting at goal.
After Eto'o caused more panic with a break that was hastily cleared, Tunisia deservedly levelled nine minutes from full-time when Ben Frej cut the ball back for Chikhaoui to strike the ball sweetly past Kameni.
With no further goals, the thriller entered extra time and it took Cameroon just two minutes to regain the lead as two Tunisian attempts at clearing a long throw-in failed and Mbia fired a low shot past Kasraoui for his second goal.
A hotly disputed free kick in the first minute of the second half presented Ben Saada with a chance to score again, but this time his effort struck the 'wall' and was cleared.