Liverpool defender Dan Agger was down in the dumps despite Denmark's vital Group E victory.
Nicklas Bendtner and Dennis Rommedahl knocked Cameroon out after Samuel Eto'o gave the Indomitable Lions the lead.
But Danish defender Agger admitted: "It was one of the worst performances we've given in a long time.
"If they'd been a bit more clinical in the first half we'd have been out of it."