Belgium's World Cup campaign came to an end in Brasilia as Gonzalo Higuain's eighth-minute strike helped Argentina to a 1-0 win and a place in the semi-finals against the Netherlands.
Marc Wilmots' men were seen as a dark horse to win the tournament but they were unable to make the breakthrough against Argentina at the Estadio Nacional de Brasilia, though Belgium forward Hazard said his team-mates could leave South America with their heads held high.
"The early goal was a big blow," Hazard told FIFA.com post-match.
"I'm very disappointed, but we've still had a very good World Cup – we achieved our original objective, after all.
"We need to make our interactions more automatic, and to do so we'll just have to knuckle down in training.
"I know that we could have done much better, but we need to keep our heads up."
Hazard added: "We were taught a useful lesson, and it'll be up to us to learn from it.
"We've got a young, highly talented team. We need to look to the future. We've already done really well to get this far."
