Libreville - Guinea-Bissau captain Bocundji Ca insists there is no secret recipe behind the sudden success of the one-time African football whipping boys, just outstanding teamwork.
"We attack and defend together," he told a radio station in the tiny, impoverished former Portuguese colony on the west African coast.
"I realise that sounds very basic, but our national football squad did not work as a team until recently. Teamwork has transformed us.
"Unwavering solidarity is the greatest factor in our successes and the fantastic support at the national stadium in Bissau has also proved crucial."
Roared on by a capacity 15,000-crowd in a stadium overlooking the Atlantic Ocean, the Djurtus (wild dogs) stunned 2012 champions Zambia 3-2 via a stoppage-time goal.
That triumph and an unexpected home win for Kenya over Congo Brazzaville a day later ensured Guinea-Bissau of a first appearance at the Africa Cup of Nations with a game to spare.
Grouped with 2017 hosts Gabon, who they face in the tournament opener this Saturday, Cameroon and Burkina Faso, Guinea-Bissau have been written off, again.
Ca says beating Zambia has given the team a belief that they can cause more shocks and emulate Cape Verde, who in 2013 reached the knock-out stage at the first attempt.
"Why should we feel inferior to our group opponents? If Zambia were in Gabon, they probably would be rated among the title favourites.
"We are determined to enjoy ourselves and the squad believes there is everything to gain and nothing to lose. Let our opponents do all the worrying."
Born in the western Biombo region of the west African nation, the 30-year-old has played all his club football in France, with Nantes, Tours, Nancy, Reims and Paris FC.
Ca is a holding midfielder, a role sure to keep him fully occupied as he seeks to cut the supply routes to stars like Pierre-Emerick Aubameyang of Gabon and Vincent Aboubakar of Cameroon.
Ca's men take on hosts Gabon in the opening game of the tournament at the Stade d'Angondje on Saturday.
Kick off is at 18:00 (SA time).