After a chastising and frustrating afternoon at the Stade d'Angondjé in Libreville, few from host nation Gabon will be looking forward to the next time the two nations meet.
A dramatic late equalizer earned unfancied Guinea-Bissau a 1-1 draw in what was its first ever game at an international tournament.
Juary Soares was the man to claim the historic goal as he rose high above a tired looking Gabon defense to glance a header beyond goalkeeper Didier Ovono.
The goal sparked wild celebrations and was the least Guinea-Bissau deserved from a Group A fixture that only sparked into life after half time.
While Gabon has top level European-based talent such as Borussia Dortmund's Pierre-Emerrick Aubameyang
and Mario Lemina of Juventus in its ranks, Guinea-Bissau is made up of players primarily plying their trade in the Portuguese lower leagues.
It is also one of the poorest nations in Africa and was being quoted as a 200-1 long-shot to win the tournament by bookmakers before Saturday's match kicked off.
"This is a moment of joy for us," Guinea-Bissau coach, Baciro Cande, later said in comments carried by the AFP News agency. "Despite our country's difficulties we managed to qualify,"
"We knew Gabon have an excellent team. We have our limits, but we had ambitions coming here and we will try to go as far as possible."
Although Aubameyang opened the scoring just after halftime with a close range finish from Denis Bouanga's cross, the hosts seldom looked the better or more experienced side.
Bounga came close just before Aubameyang broke the deadlock while Lemina headed wide when presented with a glorious chance in the first half.
But that was about as good as it got for Gabon.
Guniea-Bissau could have scored earlier had Frederic Mendy not directed his header straight at Ovono when left unmarked as the game entered its closing stages.
Inevitably, boos rained down at the final whistle as the home crowd made its displeasure known.
There had been fears about ticket sales prior to the tournament, but Saturday's match was played in front of a colorful, excitable and near capacity crowd.
Saturday's second game between Burkina Faso and Cameroon got off to an inauspicious start as the national anthems of both sides failed to play on the stadium public address system.
The Confederation of African Football later apologized for the "technical incident" via a statement, according to AFP.
On the pitch, Benjamin Moukandjo fired Cameroon in front with a spectacular free-kick strike from the edge of the area after 35 minutes.
The four-time AFCON winners spurned numerous chances to double its lead and was duly punished.
Issoufou Dayo pounced to make it 1-1 with 15 minutes to go after Fabrice Ondoa in the Cameroon goal couldn't hold Banou Diawara's strike.