Belouizdad victims of theft as they hold Mazembe in DR Congo
A spokesman for the north African club told reporters that mobile phones were among the items taken during the Group B first round match in southern Congolese city Lubumbashi.
In the same section, Kermit Erasmus scored in the final minute of regular time to seal a 2-0 win for Mamelodi Sundowns of South Africa over Al Hilal of Sudan in Pretoria.
Esperance of Tunisia went to the top of Group D by coming from behind to edge group debutants Teungueth of Senegal 2-1 in Tunis with Ghana-born Basit Abdul Khalid bagging the decisive goal.
Yakhouba Barry, who starred at the recent African Nations Championship, netted five minutes from time in Conakry to clinch a 2-0 win for Horoya of Guinea over Petro Atletico of Angola in Group C.
The highly anticipated match between Wydad Casablanca and Kaizer Chiefs in Morocco was postponed as South Africans are currently barred from the kingdom under Covid-19 regulations
Five-time African champions Mazembe were expected to make a winning start at home given their vast international experience, but they could not unlock a brilliant Belouizdad defence.
The Congolese had chances right to the end with an overhit stoppage-time free-kick that was grasped by goalkeeper Gaya Merbah summing up a disappointing outing for the hosts.
While Mazembe bossed possession and territory, Belouizdad also had chances and a poor first touch let down Youcef Bechou when he was well placed to score soon after half-time.
The frustration of Mazembe coach Pamphile Mihayo with his attack showed after 52 minutes when he took off Tanzanian Thomas Ulimwengu, who had scored three times in a two-leg qualifier.
Sundowns took advantage of the draw in Lubumbashi to go top of the table thanks to a workmanlike victory over Hilal, who had won all three qualifiers without conceding a goal.
That perfect defensive record lasted just 10 minutes in South Africa before Mosa Lebusa scored, but 2016 champions Sundowns had to wait another 80 minutes before substitute Erasmus made sure of victory.
Horoya followed a similar path to victory as Sundowns, scoring in each half through Dramane Nikiema and Barry to see off the challenge of Petro.
The multi-national Conakry outfit are seeking a third quarter-finals appearance in four years while Petro hope to improve on last season when they failed to win any of six group matches.
Teungueth, who stunned three-time champions Raja Casablanca of Morocco to become the first Senegalese club to reach the group stage since 2004, rattled Esperance when Djibril Sylla scored on 33 minutes.
Taha Yassine Khenissi levelled from a penalty on the stroke of half-time after a wild clearance by a Teungueth player struck the hand of a teammate.
Teungueth goalkeeper Baye Assane slipped to the ground as he came off his line on 73 minutes, allowing Abdul Khalid to nod a cross into an unguarded goal.