The African side pushed one of the tournament favourites all the way before conceding a late winner, having entered the clash full of confidence following their opening victory over Ecuador.
The result leaves them needing a favourable result against Curacao in their final Group E fixture to strengthen their hopes of reaching the knockout stages.
Speaking afterwards, the Manchester United attacker admitted overcoming Die Mannschaft was always going to be a difficult task.
"It was a really difficult game for us, and we knew it was going to be hard because we weren't playing against a top quality team and they have players that make make a difference at any point, but we are going to learn from this and we can still go through to the next round."
Cote d’Ivoire have never made it past the group stage of the global showpiece and Diallo suggested this has also formed part of their discussions behind the scenes.