كتب : Hatem Maher
The Dervishes, back on track after a poor start to their season, thought they put the result beyond doubt when they raced into a 3-0 lead after 17 minutes.
But Smouha did not give up, mounting sustained pressure that resulted in a goal for Ghana striker Godwin Attram in the 34th minute.
Thirty-year-old striker Ahmed Belal notched a superb goal to further reduce the gap with two minutes remaining as Ismaili had some nervous moments in the closing stages but eventually clung on to their advantage to secure their fourth consecutive win.
Ismaili, who are eyeing their first league title since 2002, moved second in the table with 25 points, two behind leaders Zamalek who played a game less.
Surprise package Police Union can leapfrog Ismaili if they beat Harras Hodoud later in the day.
Promoted Smouha, who appointed Hamza Al-Gamal as the successor of sacked coach Patrice Neveu, remain second from bottom with nine points from 13 games, two adrift of safety.
Comfortable Lead
Ismaili have notably improved of late after overcoming the consequences of their disappointing African Champions League exit from the group stage.
They were helped by some inspirational displays from playmaker Abdullah Saied, who boosted his chances of earning a recall to Egypt's squad.
Ismaili claimed a comfortable 3-0 lead over Smouha as the visitors looked out of sorts in the early stages.
Striker Ahmed Ali needed five minutes to open the scoring when he superbly headed home Saied's inswinging free kick.
Winger Ahmed Samir Farag doubled the lead on 13 minutes with a fine shot from the edge of the area and Ali scored his second of the night four minutes later to widen the gap.
Smouha finally made their presence felt when the unmarked Attram slotted into an empty net after Ismaili keeper Mohamed Sobhi parried a shot into his path.
Smouha looked likely to stage a remarkable comeback when former Ahli striker Belal netted his side's second goal in the dying minutes in superb fashion.
He chested a right-wing cross, skipped past a challenger and hit a low shot into the bottom corner of the net.
However, Ismaili held on to avoid an embarrassing draw and make sure they would remain in the hunt for the league's prestigious accolade.