Setif were favoured to win the Group B matchday one clash on the strength of having won the premier African club competition a second time last year. But USM, back in the mini-league phase after 11 years, must have sensed they had a chance given the continuous failures of Setif to exploit home advantage.
The 'Black Eagles' lifted the trophy last season despite drawing all three home group games, and a previous appearance in 2010 yielded only one win, a draw and a defeat. Setif did look the likelier scorers at Stade du 8 Mai until USM snatched two goals within 13 minutes during the second half.
Setif coach Kheireddine Madoui, who guided the club to African glory last year, reacted by introducing El-Hedi Belameiri and Ilyes Korbiaa. The double substitution worked with Setif laying siege to the USM goalmouth and Korbiaa halved the deficit six minutes from time. But 2003 Champions League semi-finalists USM survived the onslaught and host El-Merreikh of Sudan in a top-of-the-table July 10 fixture.
Striker Bakri Al-Madina starred as Merreikh triumphed 2-0 against Algerian visitors Mouloudia El-Eulma in Omdurman, across the Nile river from Khartoum.
Adel Naamane diverted a seemingly harmless Al-Madina cross past goalkeeper Mohamed Ousserir and into his own net after just six minutes. The early goal set the tone for the first half with the hosts executing the pre-match rallying cry of Franco-Italian coach Diego Garzitto to "attack, attack, attack".
Ghanaian Francis Coffie and Nigerian Solomon Jabason were among the Merreikh attackers who came close to increasing the lead. Al-Madina was guilty of wasting chances, but atoned 11 minutes into the second half by scoring from close range after Coffie set him up.
A serious situation for Eulma worsened just past the hour when Naamane was sent off for a foul on Al-Madina. Eulma, hoping to become only the second lower-division club after Setif in 1988 to win the Champions League, were denied a late goal when goalkeeper Salim Omar foiled Walid Derrardja.
Another Sudanese club, El-Hilal, are away to four-time champions TP Mazembe in the Democratic Republic of Congo on Sunday when Group A kicks off. The final matchday one fixture has Smouha of Egypt hosting Moghreb Tetouan of Morocco in Mediterranean city Alexandria.