Ajax attacker Viktor Fischer believes Tuesday night's 2-1 Champions League win over Barcelona is a wake-up call for the club.
The Eredivisie side stunned the Liga champions at the Amsterdam ArenA, with Thulani Serero and Danny Hoesen putting the home side 2-0 in front by half-time.
Joel Veltman was then sent off for fouling Neymar in the area, with Xavi slotting home the resulting penalty, but Ajax held on for all three points.
"This is what we dreamed of and for which we have worked so hard," the 19-year-old told reporters after the game.
"Maybe this is our wake-up call, the great experience that we need when we want to play more often like this. If we do this all the time, we can win against anyone. It says a lot about how much quality our team has got.
"At 2-0 I really felt we could win the match.You see often that Barcelona come back from 1-0 down, and then end up winning anyway.
"That has been the difference. But it could have been even better if we did not get the red card. In my experience, we played as good as Barcelona. I cannot remember that we've played better over the first half."
Ajax will travel to Milan for their final group stage clash knowing that only a win will be enough to see them qualify for the knockout stages, with only a point separating the two sides in Group H.
He added: "We're all in now. It will be a final in Milan. If we can win against Barcelona, we also can win against AC Milan. But we have to respect the opponent. They're still a great team."
Barcelona remain top of the group on 10 points, with Milan in second on eight points and Ajax a point further back in third, while Celtic are bottom.