كتب : Omar Zaazou
A second-half strike by star midfielder Oussama Darragi was enough for the Tunisians, who were inspired by an outstanding performance from keeper Moez Ben Cherifia, who managed to keep a clean sheet.
The win lifts last season's runners-up to top spot on six points, leading on goal difference from Cameroonian outfit Coton Sport, who also edged out Angola's Recreativo Libolo 2-1.
Esperance were Champions League finalists three seasons in a row, as they were crowned winners on 2011 before losing the title to Ahli last season.
In Group A, Orlando Pirates comfortably lead with seven points after beating Egypt giants Ahli and Zamalek.