Jose Gimenez headed intensely into the net in the 90th moment as he met Carlos Sanchez's free-kick to give the South Americans a triumphant begin in Russia.
Uruguay had been the better side as Luis Suarez had missed four shots and Edinson Cavani had hit within a post with a 25-yard free-kick.
Salah, who scored 44 times for Liverpool this season, remained an unused substitute as he keeps on recuperating from shoulder damage managed in a month ago's Champions League last.
Without Salah, Egypt did not have a front line and had looked on course to acquire a point in their first match at a World Cup finals since 1990 preceding Gimenez's late objective.
Suarez off shape yet Uruguay win it
It had looked like being a baffling evening for two-time World Cup champs Uruguay, with Barcelona forward Suarez shockingly off a frame.
He was showing up and was playing in a World Cup finals diversion out of the blue since being prohibited from all football-related movement for four months for gnawing Italy protector Giorgio Chiellini amid Brazil 2014.
However, at the Ekaterinburg Arena Suarez demonstrated inefficiently.
He shot off target right off the bat, scraped a shot wide when open just six yards out and was then twice denied by Egypt goalkeeper Mohamed El-Shenawy – who spared one shot with his legs and after that prevented Suarez from taking the ball around him.
Uruguay completed the match unequivocally with El-Shenawy making a phenomenal one-gave spare to push away Cavani's well-struck exertion from the edge of the punishment region late on.
Cavani later hit the post with a beautiful 25-yard free-kick before El-Shenawy was beaten in the 90th moment.
