The White Knights defeated the Red Devils 3-1 at the weekend thanks to goals from Mostafa Mohamed and Osama Faisal after Yassir Ibrahim of Ahly had cancelled an Ahmed Sayed strike.
It was the first loss of the season for record eight-time African champions Ahly after 18 victories and two draws under Swiss coach Rene Weiler.
Ahly have 54 points with 13 rounds remaining, Zamalek 42, Pyramids 39 and Al Mokawloon Al Arab 37.
With Ahly set to finish first, there is a three-club contest for second position and the prize of being the other Egyptian representatives in the 2021 CAF Champions League.
Own-goals played decisive roles in the fortunes of Pyramids and Mokawloon, who trail second-place Zamalek by three and five points respectively.
A Mohamed Nady own-goal in stoppage time gave Pyramids a 2-1 win at Smouha while Mokawloon fell 1-0 away to Aswan after Ahmed al Shimi put the ball into his own net.
Leaders Raja Casablanca and their three closest challengers for the Moroccan Botola Pro 1 title had their weekend fixtures postponed due to the coronavirus pandemic.
The setbacks came after officials ordered all 16 clubs to stay in hotels or sport centres when they are not training or playing instead of letting players return to their homes.
Raja have 45 points as they seek to become champions for the first time since 2013, five points more than Wydad Casablanca, Mouloudia Oujda and Renaissance Berkane.
Close encounters have been a feature of the South African Absa Premiership since the season restarted this month after being suspended in March due to the COVID-19 outbreak.
Fourteen of the first 26 matches were drawn, 10 won by one goal and the other two by two goals, including a stunning 3-1 triumph for Bloemfontein Celtic over leaders Kaizer Chiefs.
The biggest crowd-pullers have fared poorly in four matches each behind closed doors with Chiefs dropping seven points and second-place Mamelodi Sundowns and Orlando Pirates nine.
Tunisian Ligue Professionnelle 1 title-holders Esperance retained a 10-point lead over CS Sfaxien with five rounds left after the clubs achieved contrasting victories.
Four-time African champions Esperance edged seventh-place Stade Tunisien 2-1 in a Tunis derby through goals from Algerian Abderrahmane Meziane and Youssef Mosrati.
Goals during the final six minutes from Jassem Hamdouni and Walid Karoui sealed a surprisingly comfortable 4-0 triumph for Sfaxien at sixth-place Ben Guerdane.
Young Buffaloes have been declared Eswatini (formerly Swaziland) champions after the Premier League was cancelled with eight rounds to go because of the coronavirus.
The standings after 18 rounds were considered final and Buffaloes had an eight-point lead over Mbabane Swallows while defending champions Green Mamba occupied fifth position.
Buffaloes' only previous title came in 2010 and they will hope their second Champions League appearance brings more joy after crashing 7-0 to Zambian side Zesco United nine years ago.