As World Cup qualifying draws to a close around the globe in the next seven days, you will be hard pressed to find a more ill-willed, bad-blooded and potentially explosive denouement to any campaign than the one likely to unfold when Egypt face Algeria at the Cairo International Stadium on Saturday afternoon.
The pre-match atmosphere has become so heated that Fifa has warned both national associations to behave. "We feel it is timely to remind you that Fifa is clearly monitoring all the activities around this match-day," the world governing body said in a letter. Fifa officials will arrive in the Egyptian capital today, earlier than is usual, to try to ensure a modicum of calm. It is a tough ask.
The rivalry in its simplest terms, confined solely to the current dash to South Africa, is only a fraction of the story. Egypt, or the Pharaohs, were the hot favourites to make it out of Group C in the final phase of African qualifying, ahead of Algeria, Zambia and Rwanda.
They are the reigning African Nations Cup holders, having defended their 2006 title in 2008. Their top club, Al-Ahly, are the dominant force in the African game, and provide the backbone of the national side. Egypt felt bullish that they could shake the so-called "curse of the Pharaohs" that has seen them qualify for two World Cups, in 1934 and 1990.
But Algeria, aka Les Fennecs – The Desert Foxes – who are also hoping for a third finals, after 1982 and 1986, had other ideas. They, like Egypt, took 10 points from four games against the "also-rans", and then in the key head-to-head in the group to date, on home turf in June, beat Egypt 3-1 to take the box seat in the section. Algeria are therefore three points clear with one to play, and with a better goal difference of four. If they don't lose on Saturday, they will qualify. If they lose by one goal, they will still qualify. But if Egypt win by three goals, they will go through. And if they win by two goals, the group will be decided by a "winner takes all" match, to be played at a neutral venue a week today, 18 November.
The rivalry in a historic context is more brutal. This weekend's game echoes a scenario from 20 years ago, when the final qualifier for Italia '90 pitched the same nations together into what became an orgy of violence, on and off the pitch. Egypt needed to win the game, played in Cairo. Algeria needed a draw. Egypt won 1-0 thanks to a goal by their legendary striker Hossam Hassan, whose 22-year playing career ended only in 2007 after winning more than 40 titles and trophies for his clubs and country.
Euphoria on the pitch and in the stands was wrecked by bloody riots and fighting on the terraces, in the streets, in the tunnel, and even, most infamously, at the post-match reception, where the Egyptian team doctor lost an eye after being hit by a broken bottle. One of Algeria's best ever midfielders, Lakhdar Belloumi, was convicted in his absence for that attack, and Interpol issued an arrest warrant. The player always maintained his innocence, but only after another individual was named as the assailant was the warrant rescinded this year, when Belloumi was finally cleared.
Egypt's captain, Ahmed Hassan, stirred the pot recently by saying: "The stadium might accommodate only 80,000 spectators, but I would like to tell the Algerian players that the 80 million Egyptians will be present. The venue will turn into a stadium of horror."
This week, Hassan's Algeria counterpart, Yazid Mansouri, has spoken of playing "the match of our lives" while Hassan has talked of "the most important moment of our [Egypt] careers... our generation has dominated African football for the last few years, but only qualifying for the World Cup would put the proper seal on that. We believe in God and in our own quality and we know we deserve this qualification."
Yet Algeria's young squad, which for Saturday's game comprises players making a living in Algeria, Germany, England, Scotland, Portugal, France, Italy, Qatar and Greece, now stand on the verge of a major upset. If they get through, next summer the world will get to scrutinise talents including Lazio's Mourad Meghni, a French-born midfielder known as "petit Zidane".
British clubs will potentially be sending Nadir Belhadj and Hassan Yebda (from Portsmouth), Hameur Bouazza (Blackpool), Kamel Ghilas (Hull) and Madjid Bougherra (Rangers) off to do World Cup duty for Algeria.
It would be a heady trip for many involved. Before the home game with Egypt in June, Algeria's veteran coach, Rabah Saâdane, who led his country to the 1986 finals in one of four previous stints in charge, was so stressed at the pre-match press conference he broke down in tears. Nobody batted an eyelid. It's just what the fixture does to you.
Saâdane is driven by emotion in any case. In the build-up this week, he has based his players at the Italian national team's base in Coverciano, Florence. Why? "Because Italy became the World Cup champions after preparing in the same place before moving to Germany [in 2006]," he explained.
Egypt's coach, Hassan Shehata, admits: "I'm stressed. The responsibility is very high on my shoulders."
Two other African qualifying sections are also going to the wire. In Group A, Cameroon, under the charge of former Rangers manager Paul Le Guen, and Gabon, seeking a debut finals, are vying for top spot with a game left each. Cameroon are a point clear but face a tricky trip to Morocco while Gabon, managed by Alain Giresse of France's famous Euro '84 midfield, go to Togo.
In Group B, Tunisia or Nigeria will progress at the other's expense. Nigeria play in Kenya, needing a win and hoping Tunisia do not beat Mozambique away.
Out of Africa: How the qualifying groups stand
African Group A
Remaining fixtures (Saturday, 15.30): Morocco v Cameroon, Togo v Gabon.
African Group B
Remaining fixtures (Saturday, 13.00): Mozambique v Tunisia, Kenya v Nigeria.
African Group C
Remaining fixtures Rwanda v Zambia (13.30), Egypt v Algeria (17.30).
Group D won by Ivory Coast. Group E by Ghana
Gabon can qualify if they win and Cameroon drop points. Tunisia must win to guarantee progress because of inferior goal difference.