A mass brawl marred Al Sadd's 2-0 away win over South Korea's Suwon Bluewings in the first leg of their Asian Champions League semi-final on Wednesday with fighting halting play for 10 minutes and three players being sent off.
Coaching staff and players from both sides fought on the pitch at the Suwon World Cup Stadium following Al Sadd striker Mamadou Niang's controversial second goal in the 81st minute.
In some appalling scenes, players could be seen kicking at each other, while others ran away from the fighting as a number of scraps took place across the field.
The Koreans were unhappy that Al Sadd had quickly restarted play and set Niang through unopposed to round goalkeeper Jung Sung-ryong and score.
Before the controversial goal, Suwon had allowed the ball to go out of play after one of their players went down with a head injury in the Al Sadd area.
The game then restarted with Al Sadd forward Kader Keita passing to Niang as Suwon players, slowly walking back to their positions thinking their team mate was still being treated, were unaware the referee had allowed the game to continue.
"Clearly, Yeom Ki-hoon had put the ball out and I think it is the situation when our players should get it back," Suwon coach Yoon Sung-hyo told reporters.
"The opposition scored an ungentlemanly goal but there's nothing we can do about it."
Suwon players and coaching staff remonstrated with the referee and then their Al Sadd opponents as fighting broke out in dreadful scenes that will surely lead to heavy sanctions by the Asian Football Confederation (AFC).
Fans vented their frustration by throwing objects on to the field during the scuffles with one supporter running on to the pitch.
After things had calmed down, Singaporean referee Malik Abdul Bashir showed a red card to Suwon's Stevica Ristic and Al Sadd's Keita but he could have easily awarded more such was the scale of the fighting.
Al Sadd coach Jorge Fossati said the pressure of defending for long periods had led to the mix up in not returning the ball to Suwon.
"There were two players injured and my players were feeling a little pressure emotionally as Suwon were continually attacking," the Uruguayan explained.
"Of course, I don't want to defend the second goal but I think that Niang lost his head and made the decision to attack by himself."
Niang was sent off shortly after collecting a second yellow card for kicking the ball away as the final minutes were played out amid a simmering tension and a number of rash tackles by both teams, who meet in the second leg in Doha next Wednesday.
Champions League controversies continue to follow Al Sadd who could consider themselves fortunate to be in the last four.
The big-spending Qatari's lost both matches in their quarter-final only to be awarded a 3-0 first leg win by the AFC after Iranian opponents Sepahan were deemed to have fielded an ineligible player.
The early action in Korea on Wednesday had been placid with no sign of the trouble to come as Suwon enjoyed the majority of possession but Al Sadd comfortably restricted them to long-range efforts.
Suwon, who lost the Korean FA Cup final on Saturday, struggled in the final third throughout the game and Al Sadd took advantage to grab the lead in the 69th minute through Senegal striker Niang.
The dangerman won possession and broke down the left before cutting in and his right foot shot from 20 metres deflected off his own player and wrongfooted the keeper for a vital away goal.
The former Olympique Marseille and Fenerbahce striker was a thorn in the side of the Koreans all evening as their 16-match unbeaten home record in the competition ended in front of a sparse crowd.
Suwon and Al Sadd are bidding to reach their first Champions League final but their chances of lifting the trophy next month will be hampered with a number of suspensions likely as a result of Wednesday's incidents.
Twice winners Al-Ittihad of Saudi Arabia host South Korea's Jeonbuk Motors later on Wednesday in the other semi-final.comments