Zamalek maintained their five-point lead over Ismaily at the top of the Egyptian Premier League table following a goalless draw on Monday.
Playing away from home, the defensive-minded Zamalek seemed content to pack midfield, restricting Ismaily to some tame efforts and securing a share of the spoils.
Zamalek survived a late Ismaily onslaught to keep their lead at the top intact, although defending champions Ahly move closer to them with a win over Gouna on Tuesday.
Ahly, lurking in third place, could close to within four points of their arch-rivals, who are seeking to end a league drought stretching back to 2004.
Zamalek coach Hossam Hassan opted to implement a cautious strategy that saw him field three central midfielders in Ashour Al-Adham, Hassan Mostafa and Ibrahim Salah, who was included in the starting line-up following a lengthy absence due to technical reasons.
Ismaily were the attacking-minded side, playing with two strikers who were flanked by two attacking midfielders.
A dull affair of few goal-scoring chances, the first half witnessed little excitement as Zamalek’s steadfast midfield and backline kept the Ismaily forwards at bay.
Nigerian-forward John Owoeri was Ismaily’s liveliest performer with some darting runs down the left flank, but he was hardly effective.
Winger Mahmoud "Shikabala" Abdel-Razek tested Ismaily’s stand-in keeper Mohamed Fathi with a long-range free kick after 23 minutes.
Fathi, who deputized for the injured Mohamed Sobhy, blocked the shot to thwart Zamalek’s first real attempt on goal.
Playmaker Abdullah Saied could have put Ismaily in front three minutes later but he failed to connect with a pinpoint cross from the right, despite being unmarked in the area.
Ismaily had the better possession in the early stages of the second half and spurned a clear-cut chance one minute after the restart.
Saied gathered a loose ball in the area after a defensive lapse but fired over the bar with the goal at his mercy.
Zamalek replied at 64 minutes when a curling shot by Hassan Mostafa was palmed away by Fathi.
The match was stopped for a few minutes shortly afterwards after Ismaily fans hurled stones and bottles onto the running track. TV cameras caught a man getting treatment on the track after he was apparently struck by an object thrown from the stands.
Ismaily laid siege to Zamalek’s area in the final 15 minutes and were unlucky not to score a decisive goal, after keeper Abdel-Wahed El-Sayed pulled off some impressive saves to block their shots.
Zamalek were also grateful to left-back Mohamed Abdel-Shafy, whose stoppage-time goal-line clearance kept the score goalless.