The winger found the back of the net as Yannick Ferrera's side registered a 3-0 away triumph at Stade Le Canonnier.
It was his fifth goal in eight league matches involving seven starts so far this season.
Apostolos Vellios broke the deadlock in Saturday's game with a cool finish in the 11th minute, having been set up by Aleksandar Boljevic.
Jur Schrijvers then made it 2-0 for the visitors in the 39th minute, before Ampomah sealed victory with a 74th minute effort.
The win has taken Beveren to 13th on the table, three places ahead of Mouscron.
Ampomah has been his side's star man so far this season as his five goals put him up as the club's leading scorer.
He will once again be relied on for inspiration when Beveren host KV Oostende in their next game on October 6.