File photo of Angola s Petro Atletico (Photo: the club s official Twitter account)
Tiago Azulao converted a penalty in the 33rd minute for what proved to be the winner as Atletico claimed a second successive win, having beaten Morocco's Wydad 2-1 in their previous match.
Atletico, who also held Egypt's Zamalek to a thrilling 2-2 draw in Cairo in their opening game, top Group D with seven points, four ahead of Wydad and five clear of Zamalek.
Wydad and Zamalek will have a chance to trim that gap when they clash in the other group game in Casablanca later in the day.
In Group C, Algerian side CR Belouizdad struck in stoppage time to beat Botswana's Jwaneng Galaxy 2-1 away.
Substitute Kheireddine Merzougui came off the bench to break the deadlock on 77 minutes but Gilbert Baruti brought Galaxy level seven minutes later.
However, Merzougui scored again three minutes into stoppage time to give Belouizdad a precious win as they moved level on five points with Tunisia's Esperance, who were held to a 0-0 home draw by Etoile Sahel (three points).
Galaxy lie at the bottom with a single point from three matches.
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