"After profound talks... it was agreed to end the co-operation between [coach and management] at Arie Haan's request," said Anderlecht's general manager, Michel Verschueren.
"Last night's game was the last straw," said the club chairman Roger Vanden Stock. "Pressure has been high for quite a while on fans, coaches, management... at a certain moment we had to find a solution, make changes, and Arie Haan has co-operated," he said.
Vanden Stock dismissed suggestions that the former Belgium and Anderlecht player Franky Vercauteren would succeed Haan in the long term. "Vercauteren has always said that his task was the junior teams. He confirmed that again today," Vanden Stock said.
Vercauteren and the deputy coach, Jean Dockx, will, however, take over from Haan until a new coach is appointed, Verschueren said.
Haan, who played for Anderlecht between 1975 and 1981, signed an 18- month contract last December, two months after he was sacked by the Dutch club ,Feyenoord. It was a second spell as the Anderlecht coach for for the former Dutch international midfielder.
Haan, has also coached the German teams VfB Stuttgart and Nuremberg, the Belgian clubs Antwerp and Standard Liege, and the Greek side PAOK Salonika.
Before last weekend's 3-0 victory at Germinal Ekeren, Anderlecht had failed to win any of their first five league games, a run which saw them slump to the bottom of the league for the first time in their history.