Ajax beat Feyenoord 2-1 to reach the Dutch cup final, but the match was overshadowed by an incident in which Ajax’s Davy Klaassen was wounded by an object thrown from the crowd.

Feyenoord are certain to face sanctions over the incident in the 61st minute of the game in Rotterdam, which led to referee Allard Lindhout leading the teams back into the dressing-room, with Klaassen’s head bleeding profusely.

A row between the two captains, Tadic and Orkun Kökçü, triggered jeers from the crowd and a shower of objects, including cigarette lighters, one of which struck Klaassen on the back of the head.

After 30 minutes of negotiations in the tunnel, the players re-emerged and the game resumed, though Klaassen lasted just two more minutes before coach John Heitinga had to replace him with Brian Brobbey.

Police said they had arrested a 32-year-old man from Roelofarendsveen, near Leiden, who is suspected of throwing the object that struck Klaassen.

Wim Groeneweg, chair of the ACP police union, said it was time for the KNVB to take ‘decisive action’ against football hooligans.

Schandalig gedrag van ‘supporter(s)’ bij wedstrijd #feyaja in de Rotterdamse Kuip. Hier kan doortastende optreden van de @KNVB niet uitblijven. Geweld rondom voetbalwedstrijden is ontoelaatbaar en wakkert de discussie over (uit)publiek rondom wedstrijden verder aan. #knvbbeker https://t.co/lc7yu0dfFZ

— Politievakbond ACP (@Politiebond) April 5, 2023

‘This behaviour from these kinds of “supporters” goes beyond all boundaries and ruins an enjoyable night of football for a lot of people. It’s very expensive for our society and our police capacity to keep things in check.’

Ten minutes before the violence erupted Klaassen had scored what turned out to be the winning goal, bundling in a loose ball after Feyenoord’s defence had failed to clear shots by Dusan Tadic and Steven Bergwijn.

The incident is the latest chapter in a turbulent history between the two sets of supporters. Ajax fans have been banned from De Kuip stadium since 2009 and the Rotterdam club hung nets from the stands during the last league game to prevent objects being thrown onto the pitch.

For the cup semi-final the nets were removed on the side of the ground where the trouble flared at the request of TV broadcasters who wanted an uninterrupted view.

Early lead

Ajax were gifted an early lead in the 13th minute when Marcus Pedersen en Alireza Jahanbakhsh collided with each other as they tried to cut out a cross, leaving Dusan Tadic free to smack the ball into the net.

Jahanbakhsh had a chance to atone for his error shortly afterwards, but shot straight at Geronimo Rulli from close range.

But on the stroke of half-time the Iranian was released down the right-hand side and placed a pinpoint cross on the head of Santiago Gímenez, who steered the ball beyond Timon Wellenreuther.

Feyenoord had the best chances after the restart, with Gímenez going closest with a header five minutes before full-time, but Ajax held out and will return to Rotterdam on April 30 to play PSV Eindhoven in the final.