Algeria's Riyadh Mahrez blasted a free-kick past Daniel Akpeyi in Nigeria's goal, deep into stoppage time to send the Desert Foxes through to the Final of the Total Africa Cup of Nations.
Ighalo had earlier in the second half scored a penalty to cancel out a Troost-Ekong first half own goal.
Soccernet takes a look at some of the issues the match brought alive.
Green Jersey Is Cursed
Football has no room for superstition but there are times when the unreal seems to become common place. This is one of those times.
The Super Eagles have not had much luck when sporting the grass-green jersey. It was the jersey we adorned when we lost to Croatia in our first game at the 2018 World Cup.
In the group decider against Argentina when the Eagles needed at least a point, a few controversial calls went against the Nigerians including a penalty call VAR denied.
Argentina scored a late winner.
Nigeria had on the green jersey.
Back to the AFCON.
Debutants Madagascar got one over the green jersey wearing Eagles.
On Sunday night it was the ill-luck jersey yet again. And true to colour, Gernot Rohr's men conceded a Troost-Ekong own goal and then went on to lose the encounter in added time.
Akpeyi is a fine carpenter
But a terrible goalkeeper.
Whoever advised Rohr to make the South Africa based custodian his number one at this tournament is not a friend of the Nigerian people.
Akpeyi's handling is poor. His distribution is terrible. His lack of composure rubs off negatively on the defense.
Nigeria is in short supply of goaltenders at the moment but we can't have Akpeyi as our last resort.
Ikechukwu Ezenwa, with all his shortcomings, would have done better.
Rohr is tactically deficient
We played against an Algerian side that were better organised, and much more well-drilled than the Super Eagles.
Technically they were at par with the Super Eagles' players but tactically, we were miles behind the Desert Foxes.
And when scores were even and the players needed some inspiration from the bench, the German tactician (pun intended!) threw in Henry Onyekwuru, a player who had not featured at all at the tournament.
We were lucky to score through a VAR-given penalty but Algeria deserved to go through.
The Defense needs Surgery
William Troost-Ekong has been superb since day one. Kenneth Omeruo gave his best every time he was called upon.
Chidozie Awaziem earned his shirt. Jamilu Collins came back and put in a decent shift.
Individually, this bunch cannot be faulted. But together, they have been woeful.
The six goals we have conceded at AFCON 2019 is the most of any team that made it to the semifinals.
You don't win titles with such a huge leak.
Miss-placed passes, lack of communication, lack of positional awareness, a terrible keeper behind them and the likes have come to haunt the team tonight.
Going forward, a lot has to be done to correct these glaring lapses.
The Future Is Bright
The semifinal loss will hurt. But after the pain subsides, fans of the Super Eagles will look back at this tournament, review it and see it was a success.
Yes, we could have returned with the trophy.
But the team is coming home with something almost as good – a bunch of young, talented – now experienced – players ready to shoulder the football burden of a strong, soccer-crazy nation.
Wilfred Ndidi, Peter Etebo, Samuel Chukwueze, Samuel Kalu and a few others are below the age of 23 and still have at least a decade of top level football ahead of them.
The future cannot look any brighter.
