It is not the first time Nigeria international Iheanacho has come to Celtic’s rescue in recent weeks.
The former Manchester City and Leicester City striker has only made eight starts since signing on transfer deadline day in September.
The 29-year-old still looks short of full fitness, but has now scored four times in his past five of 12 games off the bench.
Two of those came in extra time as Celtic progressed to the Scottish Cup final at St Mirren’s expense, while the others were league winners in Dundee and Edinburgh.
No wonder O’Neill described him as a “super impact player”, the latest coming after he controlled a corner on his chest before delivering a clinical finish.
Former Celtic midfielder John Collins described it as a “tremendous bit of composure in a packed box with bodies all around him”.
“Iheanacho has a good awareness of what’s round about him,” he said. “He can take it in and you can play one-twos off him, but what he doesn’t have is legs to start a game.
“So the manager has a decision to make. Do you have him on the bench when games are usually won in the last 20 minutes?
“I think he’ll be a bench player used for the last minutes until the end of the season. But there’s every chance he could be a hero at the end of the season.”
Former Celtic goalkeeper Pat Bonner also praised Iheahacho for his recent impact but doubts he will ever get back to the levels of fitness required to be a regular starter.
However, might O’Neill be forced to turn to the Nigerian given Maeda, who has sprung to life himself with four goals in his latest three outings, ended the game limping off holding his boot?
There is no definitive news yet about the extent of the Japan forward’s injury. However, O’Neill said he “desperately hoping he will be okay” before next Sunday’s final, potentially crucial, Old Firm derby of the season.