After a first half in which Orlando Pirates managed to soak in the pressure of some relentless attacking by MC Alger, the Buccaneers finally got the breakthrough in the second period.
Having netted twice against CR Belouizdad in Algeria last November, Mohau Nkota rose from the bench to finish a Relebohile Mofokeng feed on 65 minutes and the attacker had only been on the pitch for five minutes after he was introduced.
Shortly after, the hosts' captain Ayoub Abdellaoui had a goal disallowed after the referee ruled that Pirates goalkeeper Sipho Chaine had been obstructed.
It was an important victory for the Buccaneers and Algeria seems to be a fertile hunting ground for Nkota, who grabbed a brace against CR Belouizdad in the group stage.
After Tuesday's 1-0 victory, the Buccaneers have now gone for 11 Champions League matches unbeaten this season.