And former club and national coach Van Himst astonishingly labelled Hoops a ‘team of peasants.’
The Premiership leaders need only avoid a 3-0 defeat at home to the Brussels club next Tuesday to secure their place in the Europa League.
That is largely thanks to Celtic’s 3-0 win at Parc Astrid in September, when the hosts were managed by Rene Weiler. The Swiss coach has since been replaced by Hein Vanhaezebrouck.
Former striker Van Himst savaged Celtic as he reviewed Vanhaezebrouck’s progress since taking over.
Van Himst, 71, spent 26 seasons as an Anderlecht player. The club icon then coached them between 1983 and 1986.
He won 81 Belgium caps, scoring a joint-record 30 goals which was only broken by Manchester United striker Romelu Lukaku earlier this month, and ended a five-year stint as national coach in 1996.
Van Himst said: “We should never have allowed ourselves to lose to a team of peasants like Celtic.
“They were a bunch of woodcutters. It was one of our worst matches ever in Europe, and we didn’t even muster an attack. Under Rene Weiler we just went backwards.
“Hein Vanhaezebrouck is not doing anything special. He does some good things, but you can’t say it is anything out of the ordinary.
“His progress is normal. What could he do better? Win the games against Paris Saint-Germain or Bayern Munich?
“But the fact the team has been knocked out of the Champions League is not his fault.
“However it is still possible to play champagne football these days - just look at Barcelona.
“Hein is on the right road towards achieving it. If anyone can do it, he can.”