AZ condemned Ajax to just their second home league defeat of the season to move level on points with fourth-placed Feyenoord in the Eredivisie table this evening.
The hosts, who remain 12 points behind league leaders PSV Eindhoven as a result of the defeat, were reduced to 10 men before Aron Johannsson got the only goal of the game to hand AZ the spoils.
In a fixture that had provided 22 goals in the last five league meetings, it was a surprisingly low-key opening 45 minutes as neither team could find a breakthrough.
The balance of the tie tilted in the visitors' favour shortly after the hour mark, however, when Johannsson span away from Nikolas Moisander before going down under the challenge of the Finnish defender.
The contact looked to be minimal, but referee Pol van Boekel opted to show Moisander a straight red card due to him being the final defender.
It was Johannsson who had the deciding say in the match too, flicking home Simon Poulsen's drilled low cross from close range with a little under 15 minutes remaining.
Ajax could not find a response in the closing stages as they slumped to a second consecutive defeat and a third match in a row without scoring.
