Clashes between police and spectators in Tunisia delayed a CAF Champions League quarter-final by 45 minutes on Saturday before local club Esperance survived a tense finish to march on.
Esperance drew 1-1 with Algerian visitors JS Kabylie to advance 2-1 on aggregate to a semi-final showdown with Al Ahly of Egypt.
Mohamed Ali Ben Romdhane gave Esperance a 49th-minute lead and Adem Redjem levelled with five minutes of regular time remaining.
Including added time, Kabylie had 12 minutes to score again and win overall on away goals, but failed to do so.
After a goalless first half, video footage showed police firing tear gas into a section of the crowd occupied by supporters wearing the colours of Esperance.
Pleas from several Esperance players to the crowd to stop throwing objects on the pitch were intially ignored at the national stadium in Rades on the outskirts of Tunis.
Order was eventually restored, however, and the second half of the second leg kicked off 45 minutes behind schedule.
Ahly, who have featured in five of the last six Champions League finals but won only two, drew 0-0 with Raja Casablanca in Morocco to qualify 2- 0 on aggregate.
Raja squandered a great chance to halve the overall deficit in first half added time when Yousri Bouzouk slammed a debatable penalty against the crossbar.
Ahly midfielder Aliou Dieng appeared to touch the ball rather than Bouzouk in the box but, after reviewing the incident at the touchline VAR monitor, the Libyan referee pointed to the spot.
The home team wasted another golden opportunity to take the lead on the night when their leading Champions League scorer, Hamza Khabba, failed to connect with a low cross on 75 minutes.
After eliminating Raja at the last-eight stage for the second successive season, record 10-time African champions Ahly will face Esperance during May for a place in the final.
League rivalry reignited
The other semi-final will feature one of the great modern-era Champions League rivalries with title-holders Wydad Casablanca of Morocco confronting Mamelodi Sundowns of South Africa.
Sundowns ended a run of three straight last-eight losses by coming from behind to complete a double over Chabab Belouizdad of Algeria with a 2-1 victory in Pretoria.
This tie was effectively decided last weekend with two goals from Namibian Peter Shalulile helping Sundowns build a 4-1 first-leg lead in Algiers, and they advanced 6-2 on aggregate.
Belouizdad are no strangers to quarter-finals heartache as this was the third season in row that their Champions League campaign ended in the first knockout stage.
Needing to score at least four goals in South Africa to pull off a sensational recovery, they took the lead on 24 minutes when captain Sofiane Boucher nodded in a corner.
Sundowns captain Themba Zwane was outstanding in midfield for the home team and he levelled in the final m inute of the first half with a close-range shot after slick, short passes.
Thapelo Morena was the second-leg match-winner, pushing a cross into the net at the far post four minutes into a second half that began in sunshine and ended in torrential rain.
Wydad were the first club to qualify for the penultimate stage after edging Simba of Tanzania 4-3 on penalties after a 1-1 aggregate draw on Friday.
Trailing 1-0 after the first leg in Dar es Salaam, Wydad won the return match in Casablanca by the same score thanks to a 24th-minute goal from giant Senegalese Bouly Sambou.
It was the eight consecutive appearance in the quarter-finals by the Moroccan club and only once did they fail to go further in the competition.
