Salah had clashed with Egyptian football officials ahead of the matchday 2 qualifier in Alexandria for the 2019 finals over image-rights violations and personal security.
But once on the pitch, the Egypt superstar was quickly in the thick of the action, winning a first-minute penalty which was blocked.
After Marwan Mohsen and Ayman Ashraf goals gave the 2018 World Cup flops a two-goal edge, Salah had another penalty saved, but scored from the rebound for a 3-0 half-time advantage.
The Liverpool sharpshooter, who scored 32 English Premier League goals last season in his first campaign at Anfield, created the fourth goal for rising star Salah Mohsen.
Salah netted the fifth and Mohamed Elneny from Arsenal completed the rout with a goal two minutes into stoppage time.
It was a wonderful start for former Mexico and Japan manager Aguirre, who recently signed a four-year contract as boss of the record seven-time African champions.
He succeeded Argentine Hector Cuper, whose contract was not renewed after Egypt lost all three group matches, to Uruguay, hosts Russia and Saudi Arabia, at the 2018 World Cup.
Despite the huge victory margin, Egypt trail Tunisia in Group J on the head-to-head rule having lost 1-0 away to the north Africans in the first round 15 months ago.
Nigeria were another team who rebounded from failing to make the World Cup last-16 in Russia by winning convincingly — 3-0 away to traditional minnows the Seychelles in Group E.
Captain Ahmed Musa, Chidozie Awaziem and Odion Ighalo, from a penalty, scored for the Super Eagles, but it was home goalkeeper Dave Mussard who became the centre of attention.
– Goalkeeper pictures go viral –
Pictures of the clearly overweight 31-year-old, a part-time footballer who also works as a hotel pastry chef, went viral.
Former Dutch star Clarence Seedorf survived a scare in his debut as coach of Cameroon, who fought back to draw 1-1 with lowly-ranked Comoros in the southeastern Africa island state.
El Fardou Ben Mohamed from Red Star Belgrade gave a nation ranked 102 places below the Cup of Nations title-holders an early lead on an artificial pitch in steamy conditions.
It took the Indomitable Lions a further 65 minutes to level through French top-tier player Stephane Bahoken, and spare former Real Madrid midfielder Seedorf’s blushes.
Seedorf, whose assistant is another former Dutch star, Patrick Kluivert, survived less than six months in three other managerial posts, including AC Milan and Deportivo la Coruna.
Cameroon qualify automatically for the 2019 tournament as hosts, but are competing in Group B to gain match practice instead of having to rely on meaningless friendlies.
There was plenty of Group K drama with Zambia and shock 2017 Cup of Nations qualifiers Guinea-Bissau snatching away draws in stoppage time.
Mozambique went ahead in additional time against Guinea-Bissau only to concede in the 97th minute and had to settle for a 2-2 draw in the top-of-the-table Maputo showdown.
Belgian Sven Vandenbroeck, an assistant coach of the 2017 Cameroon Cup of Nations-winning team, debuted as Zambia boss with a fortunate 1-1 draw against Namibia.
Justin Shonga levelled for Zambia in stoppage time when his free-kick was deflected into the corner of the net in Windhoek.
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