ENPPI secured a shock 2-0 win over Zamalek to hand them their first defeat of the season in a top-of-the-table Egyptian league clash on Thursday.
In a game riddled with controversial refereeing decisions, two second-half goals from forward Mahmoud Kaoud and full-back Mohamed Nassef handed ENPPI a precious triumph at Cairo Stadium.
Zamalek had two first-half goals contentiously ruled out by the referee, as a penalty kick - which resulted in ENPPI's opener - was not also free from controversy.
Egypt Cup holders Zamalek also wasted another debatable penalty kick deep into a nine-minute stoppage time to surrender top spot to rivals ENPPI.
ENPPI had defender Ahmed Younes, who came on as a second-half substitute, dismissed for two bookable offences as they completed the last five minutes of regular time with 10 men.
The petroleum side dislodged title-contenders Zamalek from top spot. They have 33 points, two ahead of second-placed Zamalek, who are seeking to win their first league title since 2004.
Controversy starts early on
Controversy started as early as the first minute, when the referee disallowed a goal for Zamalek striker Bassem Morsy after keeper Aly Lotfy spilled Mohamed Shaaban's cross into the path of the striker who lashed home from inside the six yard box. Morsy was adjudged to have fouled the guardian.
The match was then limited to half chances for both teams, with Zamalek clearly lacking a no. 10 in central areas to feed the frontline - which featured a strike partnership of Morsy and Ahmed Ali.
However, right-sided midfielder Shaaban was able to pose threat with his precise crosses, and Ali Gabr should have done better when he headed the former's free kick cross high over the bar in the 12th minute.
Two minutes later, ENPPI's Nassef saw a free kick deflected off the wall as the ball went wide, but the home side must have wished defender Gabr's powering header found his own net before bouncing off the bar.
On the stroke of half time, Zamalek top-scorer striker Mosry had another goal disallowed by the game's official on the grounds that midfielder Moemen Zakareya had committed a foul during the build up.
More controversy to follow
The second half witnessed no genuine chances till the hour mark, which saw ENPPI shock Zamalek with the opening goal of the night.
Left-back Ahmed Samir and keeper Mohamed Abo-Gabal were largely to blame for the goal, with the former allowing ENPPI's Kaoud all the time to control the ball at the edge of the box, and the latter failing to save the forward's weak strike.
Zamalek manager Jaime Pacheco then introduced Ayman Hefni instead of Shaaban, but against the run of play ENPPI scored again, when a counter attack saw the lively Kaoud go through on goal before left-back Samir was adjudged to have felled the forward inside the box.
Amid the protest of the Zamalek players and their management, Nassef stepped up to convert the spot kick although keeper Abo Gabal got a hand to it before it went in.
With Zamalek piling up pressure but lacking the cutting edge, ENPPI defender Younes was then handed his second yellow card in the 84th minute after remonstrating against the referee to receive his marching orders.
Mosry then had a header tipped over by Lotfy three minutes from time, but the striker was in the center of further controversy when he was awarded a penalty in the sixth minute of stoppage time, only for sub Ahmed Eid to spurn it.
Zamalek remained in control, albeit with no danger against a 10-man ENPPI who emerged winners to reclaim top spot of the table.
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