Mohamed Sherif scored as title-holders Al Ahly of Egypt took a giant step toward the CAF Champions League final by winning 1-0 at Esperance of Tunisia on Saturday after pre-match clashes between fans and police saw teargas fired and kick-off delayed by an hour.
The other semi-final first leg produced a shock result with Serbian Samir Nurkovic netting on 35 minutes to give Kaizer Chiefs of South Africa a 1-0 win at Wydad Casablanca of Morocco.
In Tunisia, trouble erupted before the kickoff at the 60,000-seat national stadium in Rades near Tunis when more than the 5,000 spectators permitted under coronavirus protocols gained entry.
Police responded to taunts from an unruly crowd by firing tear gas and stun grenades as both squads abandoned warming-up on the pitch and fled to the changerooms with some coughing and others gasping for breath.
Amid fears that the clash of the north African giants would be called off, order was restored and Ahly agreed to play after a one-hour delay having received a written pledge guaranteeing their safety.
The showdown between nine-time champions Ahly and four-time winners Esperance was decided by a 67th-minute goal from forward Mohamed Sherif, his fourth in the Champions League this season.
Mali-born Ahly midfielder Aliou Dieng was allowed to surge forward from his own half and pass to Sherif, who tapped in a rebound after his first shot struck the post.
It was the seventh time the Egyptian Red Devils have beaten the Tunisian Blood and Gold in 19 meetings in the marquee African club competition with eight drawn.
Ahly host the return match in Cairo next Saturday and a draw will suffice to secure a place in the July 17 final in Moroccan economic hub Casablanca.
While Ahly winning was not unexpected, first-time semi-finalists Chiefs succeeding certainly was with vastly more experienced Wydad hot pre-match favourites to build an aggregate lead.
Nurkovic was flagged offside by an assistant referee after beating goalkeeper Ahmed Tagnaouti with a shot into the corner of the net.
But a VAR review delivered a different outcome and the Senegalese referee awarded the goal.
Earlier, Chiefs goalkeeper Bruce Bvuma had deprived Wydad of the lead with a brilliant save off a header from Libyan Muaid Ellafi.
As the second half drew to a close, Chiefs had up to nine men behind the ball as they successfully deprived the two-time champions of an equaliser.
Apart from the vast gap in Champions League experience between the teams, Wydad were guided by Tunisian Faouzi Benzarti, who began coaching 42 years ago and has won five CAF club competitions.
Opposing him were Arthur Zwane and Dillon Sheppard, who were taking charge of Chiefs for just the third time as caretakers after head coach Gavin Hunt was fired last month.
Hunt had been in charge when the teams met at the group stage with Wydad winning 4-0 at home and losing 1-0 away.
Chiefs hope to become the third South African winners of the competition after Orlando Pirates and Mamelodi Sundowns.