The African champions dominated but went down 2-1 Sunday to Qatar's Al Sadd, leaving fans and players of the Tunis team furious at refereeing decisions that they felt had denied them a semi-final clash with the European champions.
At least one seething Esperance fan made it to within feet of players and officials at the end of a tense match at Toyota Stadium in Japan before he was wrestled to the ground, while supporters grappled with police in the stands.
FIFA said that it would ratchet up security for Esperance's match with the Mexicans Monterrey on Wednesday, which will decide who takes fifth place at the annual tournament of continental champions.
Esperance supporters and players were incensed after Chilean referee Enrique Osses ruled two goals out for offside—one of which looked onside—and failed to award the north Africans what looked like a penalty.
"I'm not in a position to talk about the referee's judgement," said Esperance coach Nabil Maaloul, before doing just that.
"I thought the two offside goals were goals. And I'm not sure about Al Sadd's second goal, but I think the referee made a mistake, just like the players (think too)," he said.
"The officials may have made some mistakes, but I'm not in a position to talk about their judgement."
Maaloul, who could be set to stand down after a phenomenally successful season, saw his side control most of the possession and squander several great chances, while they fell asleep at set-pieces for both the Al Sadd goals.
"We were not able to capitalise on the many opportunities. We had seven or eight opportunities that we failed to score from," he said.
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