Zamalek slumped to a 2-1 defeat to Masry in an Egyptian league game at Suez stadium on Thursday, making way for archrivals Ahly to advance into the league summit with nine games left for the Cairo giants in the season
After the defeat, the white Knights sit second on the league table with 57 points, just one point behind Ahly who are now leading the table with 58 points after claiming a 2-1 win over Maqassa on Wednesday.
Defender Eslam Abou Sleima opened the scoring for Masry five minutes before the break, while Austin Amutu doubled the seal for his side in the 56th minute.
In injury time, Zamalek defender Mahmoud Alaa scored the consolation goal for the visitors after converting a penalty.
Zamalek started the game without pressure on Masry, giving the chance to the hosts to play with ease and no fear of threat.
Moroccan winger Hamid Ahddad had the chance to open the scoring for Zamalek in the 18th minutes, but he failed to control the ball before Mahmoud Abdel-Aziz powerful shot from outside the area went wide seven minutes later.
Five minutes before the break, Masry defender Eslam Abou Sleima met Eslam Issa's cross with a nice header to open the scoring for the hosts.
Zamalek coach Christian Gross tried to intensify his attack, sending in wingers Ibrahim Hassan and Mahmoud 'Kahraba' Abdel Moneam in the 46th and 54th minutes at the expense of Ahmed' Zizo' Sayed and Hamid Ahddad, respectively.
But it was Masry who scored in the 56 minute.
A miss pass from Zamalek international midfielder Tarek Hamed was intercepted by Eslam Issa who send a nice pass to Nigerian forward Austin Amutu, who eased past Zamalek defender Mahmoud Hamdi before sending a powerful shotfrom outside the area.
The mission became more difficult for Zamalek, forcing Gross to introduce striker Omar El-Saed at the expense of defensive midfielder Mahmoud Abdel-Aziz.
However, El-Saed failed to make his presence felt.
As Zamalek intensified their offense, Masry made many counter attacks, but Zamalek Keeper Mahmoud Abdel-Rehim saved his side in many occasions.
Mahmoud Abdel-Moneam gained a penalty in the dying minutes after Masry defender Ahmed Shousha touched the ball with his hand inside the area.
After Mahmoud Alaa converted the penalty, Masry's Shousha recveived a second yellow card to exit the pitch.
However, Zamalek failed to level the score, losing the game and lost the league summit.
After the game, Zamalek's Tunisian defender Hamdi Nagguez was shown a second yellow card and shown a red one for objection to miss the White Knight's next clash against Ismaily on Thursday.