Fathi, stepping into the shoes of the absent Mohamed Salah, found the net in the 37th minute, marking his second consecutive goal for the Pharaohs since his debut strike against South Sudan in June.
Under the leadership of Rui Vitoria, Egypt further solidified their hold on top spot in Group D, amassing 15 points, having already secured their qualification before this match. Meanwhile, Ethiopia sits at the bottom with four points.
Despite an early threat from Ethiopia's Kenean Markneh in the 3rd minute, Egypt largely controlled possession, yet their dominance yielded minimal results.
Ethiopian goalkeeper Seid Habtamu shone with two outstanding saves, thwarting headers from Mohamed Abdel-Moneim and Mostafa Mohamed, while Mostafa Fathi struggled to find the target on two separate occasions.
The breakthrough finally arrived in the 37th minute when Fathi capitalized on a rebound, pouncing on a loose ball from a long-range Omar Marmoush shot that eluded the keeper's grasp.
Egypt elevated their performance in the second half, but Mostafa Fathi squandered his chances, and Mostafa Mohamed had a penalty appeal waved away after being clear on goal.
The Pharaohs lacked the decisive touch, allowing their resilient opponents to stay in contention.
Veteran Ethiopian forward Shemeles Bekele made an immediate impact upon his introduction, keeping Egypt's defenders on high alert and distributing precise passes to his teammates.
With growing confidence, Ethiopian players created chances through Bekele and Abdel Yalew, but Egyptian keeper Mohamed El Shennawy proved as reliable as ever, preserving the victory and extending coach Rui Vitoria's unbeaten streak.
Egypt is set to face Tunisia in a friendly match on Monday.
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