In one of the matches of the tournament so far, four-time champion Cameroon produced an impressive comeback to record its first AFCON victory since 2010.
But the Indomitable Lions were certainly made to work for their victory, after Guinea-Bissau's Piqueti scored what could be the goal of the tournament.
Picking the ball up inside his own half, Piqueti nonchalantly flicked it over Georges Mandjeck's head and drove into the Cameroon box, before unleashing a rasping effort past Fabrice Ondoa.
It was some way to notch your first ever international goal, but the Cameroon players weren't in any mood to be beaten, with midfielder Sebastien Siani kickstarting the comeback with a strike from 20 yards.
A defender by trade, Michael Ngadeu got the second and urged calm in the Cameroonian ranks.
Guinea-Bissau rallied to no avail and, with three points secured, Cameroon became the first nation to record a comeback this tournament and moved to the top of Group A.
In the early game, Gabon supporters arrived at the Stade de l'Amitie in Libreville hoping the Panthers could avenge Saturday's disappointing 1-1 draw against Guinea Bissau.
But it was Burkina Faso that struck first in Group A's second round of fixtures, with enforced substitute Préjuce Nakoulma getting his name of the scoresheet just past the half-hour mark.
The Stallions have never won the Africa Cup of Nations and, though they did reach the final in 2013, it appeared a shock could be on the cards.
Gabon captain Pierre-Emerick Aubameyang changed all that, winning a penalty when he was brought down by Burkina Faso's Kouakou Hervé Koffi after racing through on goal.
With 16 goals in 15 Bundesliga appearances for his club side this season, it was no surprise to see Aubameyang send Koffi the wrong way, equalizing for Gabon.
But the famous comeback wasn't to be, and Burkina Faso held on for a valuable point. Both sides must win their final Group A fixture to have any chance of qualifying for the knockout stages.