One of African football's closest rivalries will be reignited when two teams who progressed via compelling round-of-16 matches meet in the Africa Cup of Nations quarter-finals at Cairo International Stadium on Wednesday.
Surprise package South Africa have offered clear signs of resurgence at the tournament following a fallow few years in which their own fans have often questioned their players and performances.
Nigeria are as instantly familiar as their shimmering green shirts when it comes to the final four of this competition, although they will know from results so far - as well as their own malaise in losing 2-0 to Madagascar - that a semi-final spot is no certainty.
Nigeria's pedigree in this tournament makes them perennial contenders - victory would give them a sixth successive slot in the semi-finals and enhance their current run of three wins from their last four.
The three-time winners lifted the trophy in South Africa in 2013 and have lost just one of their last 11 matches - that setback against Madagascar in their final group game, when coach Gernot Rohr rested several players.
Three goals by players with plenty of Premier League experience helped them knock out reigning champions Cameroon during a frenetic round-of-16 clash in which the Super Eagles showed their ruthlessness in response to having far less possession than the holders.
Ighalo equalised and set up Arsenal forward Alex Iwobi's winner, crystallising how Nigeria's players have occasionally been unrecognisable to supporters familiar with their exploits in domestic competition.
Iwobi produced the kind of quality that Arsenal fans wish he could produce more consistently to clinch victory with a skilful finish, while former Leicester City winger Ahmed Musa, who left the Foxes last year and now plays for Saudi Arabian side Al-Nassr, brimmed with fleet-footed intent and is perhaps poised to become one of the stars of this year's tournament.
Recent AFCON form: WWLW
Recent form (all competitions): DWWWLW
With momentum often key at tournaments, South Africa entered their first knockout game as heavy underdogs against Egypt, having lost to the Ivory Coast and Morocco in Group D before sneaking through as one of the best third-placed finishers with a redemptive 1-0 win against Namibia.
The 1996 tournament winners were expected to offer minimal resistance to an Egypt side spearheaded by Liverpool's Mohamed Salah, but turned heads with a vibrant performance that impressively matched The Pharaohs in their backyard and allowed South Africa to emerge as worthy winners by the only goal of the game.
If the upset was foreseen by few, South Africa themselves seemed full of belief in spite of an inauspicious opening few matches in their campaign.
In the tradition of tournament teams not blessed with obvious stars, they demonstrated a keen resilience and committed sense of teamwork on their way to the quarter-finals, with their winning goal arriving via a lethal counter-attack as Egypt pushed men forward.
South Africa supporters - particularly those who follow the country's Premier Soccer League - were particularly relieved to see Thembinkosi Lorch grab the heroic 85th-minute winner against Egypt.
The Orlando Pirates striker is the country's current Player of the Year and helped to provide the incisive movement Stuart Baxter had urged his team to demonstrate earlier in the tournament, working cleverly in the company of Percy Tau, who won the same honour in Belgium's Proximus League last season.
Even though Salah was recovering from illness, containing one of the world's best strikers was an impressive feat by a South Africa side who have shown impressive defensive steel.
Bafana Bafana have conceded more than once in just one of their last 18 matches and recorded clean sheets in 10 of their last 17 games.
One omen for South Africa is that they have won or reached the final on both previous occasions when they have met Egypt during the final tournament: 23 years ago, a 1-0 group stage defeat preceded them winning the trophy, and they lost 2-0 to The Pharaohs in the 1998 final. Having avenged those defeats, could they provide another shock?
Recent AFCON form: LWLW
Recent form (all competitions): DDLWLW
South Africa coach Baxter spoke with satisfaction of the surprise his bold selection and relatively cavalier attacking approach sprung on their round-of-16 victims.
While the Bafana Bafana boss might seek to emulate that unpredictability by introducing more changes, the greater likelihood is an untouched lineup that will, if nothing else, reward his victorious players and please their increasingly optimistic fans.
Nigeria will receive a significant boost should John Obi Mikel return from an injury that forced him to limp out of the defeat to Madagascar.
Rohr is understandably eager to involve the former Chelsea midfielder again, and told reporters that he has been tentatively running in a bid to be ready for the quarter-final.
Now at Trabzonspor, Mikel has suggested he will not hurry his recovery and is certain of making a potential semi-final should he fail to be ready for the match with South Africa.
As well as helping Nigeria finish third at the 2006 and 2010 Nations Cups, Mikel was part of the 2013 AFCON-winning squad and appeared at the last two World Cups - and his experience has been key for the younger members of Nigeria's squad this year.
Mikel, who took part in a light training session on Sunday, could be restored as captain, while there is likely to be further good news on the fitness of Shehu Abdullahi.
The Bursaspor defender left the late group stage win over Burundi with a hamstring injury but is in contention for a starting berth after returning to the bench against Cameroon.
Levante forward Moses Simon is likely to make way for Mikel as part of a Nigeria attack that could test South Africa's flawless run of first-half clean sheets in their campaign so far.
Ighalo is the tournament's joint top scorer with three goals, and his ratio of 93 minutes per goal means he has been narrowly less prolific than Senegal and Liverpool rival Sadio Mane.
Nigeria possible starting lineup:
Akpeyi; Awaziem, Troost-Ekong, Omeruo, Aina; Ndidi, Etebo; Iwobi, Mikel, Musa; Ighalo
South Africa possible starting lineup:
Williams; Hlanti, Mkhwanazi, Hlatshwayo, Mkhize; Furman, Zungu, Mokotjo; Lorch, Mothiba, Tau
Head To Head
Nigeria's concerns will be heightened by the most recent meetings between the two teams. Bafana Bafana enjoyed a 2-0 win in their encounter during the early stages of qualifying for AFCON 2019, although Rohr's men earned a 1-1 draw in the return fixture last November.
That first-leg win in 2017 is South Africa's only competitive victory in their meetings with Nigeria, although they won 2-1 in a friendly in 2004 and have not lost to these opponents in almost six years.
With the exception of South Africa's win, four of the last five meetings have been draws - perhaps the most memorable of which was in the 2014 AFCON, when former Bournemouth striker Tokelo Rantie put South Africa 2-0 up before Reading's Sone Aluko struck twice for Nigeria, including a 94th-minute equaliser.
We say: Nigeria 3-1 South Africa
South Africa made a mockery of most pre-match predictions during their confident win over Egypt, leaving Nigeria as wary of their next opponents as they were of current champions Cameroon last time out.
Despite the demonstrable danger to their prospects of reaching the semi-finals yet again, Nigeria's considerable AFCON experience should help them adapt to the unexpected - as they proved during that creditable comeback in the round of 16.
South Africa have found a formula that makes them a threat to any team and their opportunistic counter-attacking could set up sucker-punches. That risk aside, Nigeria's nous and firepower should see them through.