Ajax Amsterdam's poor season went from bad to worse after they suffered one of the biggest shocks in their history with a 3-2 loss to fourth-tier amateur side USV Hercules in the last 32 of the Dutch Cup on Thursday.

Trailing 2-0 in Utrecht after 82 minutes, Ajax looked to have saved themselves when Brian Brobbey and Chuba Akpom netted late goals to level the score.

- Stream on ESPN+: LaLiga, Bundesliga, more (U.S.)

- Hamilton: Inside Ajax's fall from grace

But Hercules netted the winner through Mats Grotenbreg in the third minute of injury time after their own coach Rene van der Kooij had given his team a 2% chance of victory before the game.

Ajax coach John van 't Schip was not present to witness his side's capitulation as he is in Australia to attend his son's wedding.

"This should not have happened," Ajax assistant coach Michael Valkanis said.

It is the first time Ajax have lost to an amateur club in the Dutch Cup. In the 29 previous meetings, they have scored at least four goals.

Ajax spent the early part of this season in the relegation zone but have since risen to fifth in the Eredivisie table, albeit they are a massive 23 points behind leaders PSV Eindhoven.

"We are having a very difficult season," Valkanis said. "But we have to continue and get everything on track."

Reuters and the Associated Press contributed to this report.