The Aston Villa midfielder was presented with a gilt-edged opportunity to reduce the deficit at 2-0, but after visiting goalkeeper Georgiy Bushchan flapped at a cross, he contrived to head wide.
Callum McGregor eventually did pull one back but Artem Dovbyk restored the two-goal lead late in injury time.
Speaking ahead of Scotland’s trip to Dublin to face the Republic of Ireland in the second Nations League clash, the 27-year-old spoke candidly about the miss.
"I was hurting and hurting badly,” he admitted.
“You make a decision in a split second. On this occasion it was the wrong one and it will probably live with me for a long, long time.
“I promised I wouldn’t watch it back but I woke up the next morning and then had to watch it. In that split second you don’t see the other side, you make a decision at the time and it was the wrong one.
“You can either dwell on it, keep looking at it and thinking what you could have changed, or you can go out and try to score nineteen times like I did against Armenia trying to avenge it.
“It didn’t work on Wednesday but I will do the exact same thing on Saturday.”
McGinn has 12 goals in 46 games for his country which he feels is a decent return, but while he bemoaned his habit of putting away the difficult chances and struggling with the sitters, he asserted that both he and the team would make up for the defeat in the future.
“The disappointing thing for me in my Scotland career is that it’s always the easier ones I seem to miss. I score the more challenging ones so I have to practice those moments and don’t be so keen to score,” he explained.
“It was a really disappointing night for me and for everyone but it’s one we are really keen to avenge.
“Even if it does take two years or four years, it’s one we will definitely do.”