ES Setif's CAF Champions League defence began poorly, with domestic rivals USM Alger winning away 2-1.
Defending CAF Champions League winners ES Setif were beaten by fellow Algerian outfit USM Alger 2-1 in Setif on Saturday.
USM Alger - who won the 2013-14 domestic title - began Group B in fine style, with second-half goals to Mohamed Seguer and Nacereddine Khoualed giving them all three points at the Stade du 8 Mai 1945.
Substitute Ilyes Korbiaa pulled a goal back with six minutes to play for ES Setif, but Kheireddine Madoui's men could not produce an equaliser as their title defence started with a loss.
The fixture represented the first competitive contest for both sides since their respective domestic campaigns finished in late May, when ES Setif were crowned champions of Algeria and USM Alger's league defence ended with a mid-table finish.