Egypt's capital crackled with fireworks and blared with horns as the soccer-crazy country reached the World Cup for the first time in 28 years as rare scenes of joy took hold of city blocks celebrating a 2-1 victory over Congo.

Winger Mohamed Salah scored twice, securing victory with a last-gasp penalty to put Egypt four points clear with one match left in their African group E qualifying campaign.

The win clinched Egypt a long-awaited spot in Russia for the 2018 World Cup finals, where the Arab world's most populous country will compete on football's ultimate stage for the first time since Italy in 1990.

"It's been 28 years and we're finally going to enter the World Cup. Today is a day of celebration for the entire country," said 41-year-old Gaber Fathy.

The raucous mood spilling out on the streets marked a respite for Egyptians after years of hardship, from IMF-backed austerity reforms that have pushed inflation to record highs to a tough law on protests that has made public gatherings exceedingly rare after two presidents were toppled since a 2011 uprising.

"You can look around and see how people are happy. This is something you never witness in Egypt," said 23-year-old Gamal Mohamed in downtown Cairo's Tahrir Square, the iconic centre of the country's once-active protest movement, which has since been quashed by tough security measures.

Egypt's President Abdel Fattah al-Sisi congratulated the Egyptian people after the match as tireless fans draped in flags turned the streets into an impromptu parade of red, white and black.

Just across the border in neighbouring Gaza, where Egypt has led a political reconciliation process, thousands of Palestinians poured into an open-air park to cheer on the second Arab country to qualify for the 2018 World Cup after Saudi Arabia.