Ati-Zigi was hooted at and suffered racist chants from the Lugano fans in the Swiss League fixture at the Cornaredo stadium.
St. Gallen lost the match with a 1-0 scoreline.
Lugano reported the unwarranted incident on their Twitter page and have assured the perpetrators would be identified and brought to book.
They wrote on Twitter:
“Some spectators would have inadequately addressed the guest goalkeeper Lawrence Ati Zigi,”
“The company “will do everything possible to identify those responsible”.”