Ahly could not come up with a positive away result at Ivory Coast's Sewe Sport as they conceded a late goal to lose 2-1 in the CAF Confederation Cup final first leg on Saturday.
Sewe went in front in the 22nd minute through a Koffi Kouame -spot kick but Mahmoud 'Hassan' Trezeguet restored parity in the second half.
As Ahly looked close to securing a 1-1 draw away from home, they paid the price of some slack defending to leak a goal with just eight minutes left from substitute Franck Guiza, who netted with his first touch after coming on.
Ahly, who are chasing their maiden Confederation Cup title in their trophy-laden history, would now need to overturn the one-goal deficit in Cairo next week to become the first Egyptian side to win Africa's secondary competition.
Insipid first half
The first half did not witness many goal-scoring opportunities for either side, with Ahly paying the price of a one-on-one chance squandered by Walid Soliman after 18 minutes.
An excellent one-two between Emad Meteb and Egypt attacking midfielder Soliman saw the latter go through on goal before the keeper came out in time to thwart him.
But Walid's miss proved costly just a few minutes later when the lively Roger Assale latched onto a long ball to break clear before keeper Ahmed Adel was adjudged to have fouled him inside the box.
Koffi Kouame made no mistake from the ensuing penalty kick, sending keeper Adel the wrong way to put his side ahead.
Garrido changes proves vital
Ahly boss Juan Carlos Garrido was quick to make changes to his unconvincing side, withdrawing Meteb and midfielder Ahmed Khairy to bring in forward Ramadan Sobhi and defender Sherif Abdel-Fadil.
The changes which proved vital afterwards were not effective outright, with Sewe coming close to doubling their lead just seconds after the break.
Ahly's lackluster backline failed to win the ball from forward Assale, whose header released Essis Aka but the latter's tame effort was easily collected by the keeper.
The Reds thought they have equalized five minutes later but Hossam Ghaly's tap in was disallowed due to a foul in the build-up.
Assale again managed to get around the pressure of Ghaly before turning and unleashing a strike that was again blocked by keeper Adel.
But the blitz of Sewe's chances still continued, with Kouame missing the target by inches when his strike from outside the box went narrowly wide.
The Sewe chance they shortly rued, however, came when Hermann Kouao missed from point blank range with the goal at his mercy after Cédric Kouadio N’Goran was allowed space on Ahly's right flank.
And against the run of play, Trezeguet managed to bring Ahly level when he chested a cross for Sobhi who then headed the ball back to him to lash the ball into the roof of the net just before the hour mark.
But there was still time for more wastefulness, and Soliman was guilty of wasting an easy header when he rose unopposed inside Sewe's box to head wide a cross from Sabry Rahil – pushed forward on the wing in the second half.
Ahly were punished with eight minutes remaining when Sewe's Guiza, who repaid the manager's faith immediately after coming on, notched the winner.
Some shambolic defending allowed him to pounce on a loose ball, which initially hit two Ahly defenders, inside the Ahly box to strike into the roof of the net.
Despite reaching the byline several times after the goal, Ahly couldn't level the scoring again – as they will now bank on their away goal a week later when they host the Ivorians in Cairo.
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