Referee Jean-Jacques Ndala awarded a late penalty following a VAR review in the closing minutes against hosts Morocco at the Prince Moulay Abdellah Stadium – prompting Senegal’s players to walk off the field in protest.
Koulibaly, who was watching from the bench due to suspension, spoke to the press afterwards about the controversial moment.
"It was really strange that the referee decided it was a foul, and it was difficult for us to accept the foul because I think that it was not a foul. After the VAR decision we had a big decision to make and we wanted to stop the game, and then players like Sadio showed a lot of character and wanted to come back out on the pitch."
The defender admitted it wasn’t easy getting back on to continue and to ultimately win the tie 1-0 in extra-time.
"It's difficult, and it's a mental game as everyone wanted to win, and we showed a lot of character in the end to become champions of Africa."
Koulibaly added that Senegal will go into the FIFA World Cup in the Americas later this year as one of the strongest teams there.
The newly crowned African champions will face Norway and France at the World Cup and he was asked about his battle with striker Erling Haaland.
"We will see. It's never about one player because you face the whole team. Erling Haaland is very talented and scores a lot of goals, but we are going to do everything to try and win. We are not going to think about it now...