Percy Tau celebrates one of his goals against Ismaily (Photo: Ahram)
The South African forward doubled Ahly's advantage on 23 minutes after a penalty from Ali Maaloul had given them an early lead before ending the match as a contest with another goal nine minutes later.
Substitute Ahmed Abdel-Kader, back from a fruitful loan spell with Smouha, put the icing on the cake with a 87th-minute goal, even though Ahly played with ten men for the last quarter of an hour after Malian midfielder Aliou Dieng was sent off for a rash studs-high challenge on an opponent.
Ahly produced a vibrant attacking display to record their biggest victory over Ismaily in 15 years and avenge a 1-1 draw last August, which saw them drop behind eventual champions Zamalek with only five matches remaining of the season.
The Red Devils moved top of the table with three points, ahead of several other teams on goal difference, including Cairo rivals Zamalek.
Ahly's league loss last season was party blamed on lack of quality in the final third, with the club moving swiftly to recruit the likes of Tau, who joined from English Premier League side Brighton, and Mozambican winger Luis Miquissone.
Both men were included in a much-changed Ahly frontline, with Tau spearheading a three-man attack comprising Miquissone and playmaker Magdi Afsha.
Although Ismaily created the game's first chance, it did not take Ahly long to stamp their authority when the referee pointed to the spot after Tunisian defender Marouane Sahraoui appeared to tumble over Miquissone.
Maaloul sent Ismaily keeper Ahmed Adel the wrong way and Tau added the second following a brilliant team move.
Afsha flicked a Dieng long ball into the path of Tau, who expertly collected the ball and nutmegged Egyptian international defender Baher El-Mohammadi to cut inside him and beat Adel at his near post with a precise low shot.
The 27-year-old made it 3-0 in the 32nd minute when he stole ahead of his marker to flick an inviting low cross from Afsha with his left foot before volleying with his right into the far bottom corner.
Ahly took their foot off the gas pedal in a slow-tempo second half but still added gloss to the scoreline with three minutes remaining when Abdel-Kader weaved his way past a couple of challengers in the area before drilling home with aplomb.
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