The Indomitable Lions have one foot in the AFCON quarter-finals after coming from one goal down to defeat their opponents and see them top Group A
Michael Ngadeu-Ngadjui struck the winner as Cameroon took control of Group A at the Africa Cup of Nations by coming from behind to beat Guinea-Bissau 2-1 in Libreville.
Four-time AFCON winners Cameroon looked to be heading for a shock defeat to competition debutants Guinea-Bissau until Ngadeu-Ngadjui added to Sebastien Siani's equaliser to put Hugo Broos' team two points clear at the top of the pool with one game left.
Guinea-Bissau took the lead after 13 minutes when Piqueti brilliantly surged from inside his own half and beat three players before slamming the ball beyond Fabrice Ondoa in the Cameroon goal.
However, the Indomitable Lions controlled possession and ground down their opponents, Siani drilling home from 20 yards in the 61st minute to set up a tense finale.
Ngadeu-Ngadjui, who made an important goal-line clearance with his side 1-0 down, completed the turnaround 17 minutes later when he guided Christian Bassogog's cutback into the bottom-right corner from just outside the box, putting Cameroon's fate in their own hands.
A draw against hosts Gabon in their final group match will be enough to secure Broos' side a place in the quarter-finals, while Guinea-Bissau will need to beat Burkina Faso to keep their campaign alive.