It took only 10 seconds of play for the FC Midtjylland forward to score what would be the matchwinner against Javier Aguirre’s men - hosts of the Afcon finals in June.
Leon Balogun and John Ogu were the only changes in the defence and midfield respectively from Seychelles win. In attack, Onuachu was handed his full debut and Moses Simon returned to start a Nigeria game after almost two years [against Zambia in October 2017] on the fringes. Henry Onyekuru completed the attacking trident as Daniel Akpeyi led from the back.
Nigeria U23 hat-trick hero Victor Osimhen returned to the bench after Wednesday's heroic showing against Libya U23.
Javier Aguirre handed starts to both Mohamed Elneny and Mahmoud Trezeguet after the duo were left out of an inexperienced starting XI in their final Afcon qualifier win over Niger.
The Super Eagles made a flying start right from kick-off, with Onuachu grabbing his first Nigeria goal in spectacular fashion after 10 seconds of play.
After the customary kick-off routine, the ball was shifted to John Ogu who made a searching pass to Onuachu. The lanky striker reacted quickly, leaving an Egypt defender chasing his shadow, before smashing a half-volley past Mahmoud Gennesh from the edge of the area.
The game restarted with both sides taking turns in dominating proceedings, but they lacked the cutting edge as aptly shown when Mostafa Mohamed headed well high from a good delivery on the half-hour mark.
Tarek Hamed received the first booking of the game after a foul on Onuachu, who had been a handful for the Egyptians. Balogun's followed swiftly, cautioned for dissent.
Iwobi outsmarted an Egyptian defender but shot tamely at Gennesh, which was the final meaningful action of the opening 45 minutes.
Ikechukwu Ezenwa was called into action before the restart, replacing Akpeyi who was rarely tested in the first half.
The first real chance of the second half went to Onuachu who could have done better to double Nigeria’s lead with a header - off Simon’s right-wing free-kick - on the hour mark.
Five minutes later, Ogu - who played with elegance at the base of the midfield - went down on the turf with a perceived hamstring problem, paving the way for Semi Ajayi’s introduction.
Ezenwa produced a double save - the first a stunning one - to keep Nigeria ahead in the game as Egypt sought to find a response to an early setback. Balogun was also instrumental in keeping rampaging Pharaohs at bay as Rohr's side started preparation for Afcon impressively.