Hungarian striker Peter Kovacs notched the precious winner in the 58th minute after heading home a cross from Garry De Graef.
The visitors had midfielder Joeri Dequevy sent off with 12 minutes remaining but held on with ten men to end an eight-match winless streak.
Egyptian striker Mohamed Al-Gabbas was included in Lierse's starting line-up while his compatriot Mohamed Abdul-Wahed missed the game due to injury.
Al-Gabbas played as a right winger and produced a fine display before being replaced with Angolan Gilberto, who left Egyptian champions Ahli in the close season, in the 75th minute.
Lierse, who are owned by Egyptian businessman Maged Sami, lie third from bottom in the league table with five points from nine games.
New coach Eric van Meir, a Lierse hero in the late 1990s during his playing days, enjoyed his first victory at the helm after replacing the sacked Aime Antheunis.
Lierse held defending champions Anderlecht to a 1-1 draw on Van Meir's debut in their previous game.