By Durosimi Thomas
BBC Sport in Tunis
DR Congo 1-2 Guinea
Masudi celebrates his opening goal for DR Congo
Guinea came back from a goal down to beat Group A rivals DR Congo at the African Cup of Nations.
Alain Masudi's volley gave DR Congo the lead, before Titi Camara's low drive and Pascal Feindouno's header sent the Guinea fans into raptures.
Guinea also came close on several other occasions, with Feindouno's delicate chip the best effort.
DR Congo's next match is against Tunisia on Wednesday, while Guinea face Rwanda.
Sunday's win by Guinea in the El Mensah stadium was their first Cup of Nations victory over DR Congo in three meetings.
DR Congo looked the better side in the opening exchanges with Newcastle's Lomana Lua Lua continually breaking clear of his marker.
The Congolese captain had several attempts on goal in the early period but each time failed to put his side ahead.
It was no surprise when the Congolese did evenutally score.
The only surprise was that it was Belgium-based Masudi whose name was on the scoresheet and not that of the Newcastle striker.
Masudi made no mistake with his volley, latching on to a Kibemba Mbayo cross in the 35th minute.
DR Congo went to the break with the one-goal advantage in tact but Guinea fought back in the second.
Midway through the half, Fode Mansare was left unmarked on the flank, allowing him to send in a perfectly placed cross for 'Titi' Camara, also unchallenged, to fire low and hard into an empty net.
Guinea were revived. Just ten minutes later, Feindouno scored from a rebound after Souleymane Youla's shot hit the post, with Mansare again the man who had delivered the decisive cross.
The goal left Guinea's fans dancing in the stands while a dispirited DR Congo appeared to have nothing left in the tank as the final minutes ticked away.
DR Congo: 1-Paulin Tokala; 3-Camille Muzinga, 4-Cyrille
Mubiala, 5-Jean-Paul Kamudimba, 14-Michel Mazingu-Dinzey
(8-Kangana Ndiwa 85); 6-Tresor Luntala, 15-Herita Ilunga,
10-Alain Masudi, 17-Marlin Piana (7-Dieudonne Kalulika 73);
9-Lomana LuaLua, 18-Marcel Mbayo (11-Kabamba Musasa 78)
Guinea: 16-Kemoko Camara; 5-Bobo Balde, 6-Schumann Bah,
13-Ibrahim Sory Conte, 17-Morlaye Soumah; 2-Pascal Feindouno,
3-Abdoul Salam Sow, 11-Souleymane Youla, 14-Ousmane Ngom Camara;
10-Aboubacar Titi Camara (9-Sambegou Bangoura 69), 7-Fode
Referee: Sharaf Abubakar (Ivory Coast)