Isgrove, who has been capped five times at under-21 level for his country, said: "I really enjoyed it. [I was told] I’d be coming on at 60 minutes, so I was just preparing in my head and warming up well just to come on and try and make an impact.
"You don’t really notice the crowd as much when you’re playing, you’re sort of in the zone and just focusing on what you’ve got to do on the pitch.”
Having fallen behind to Craig Cathcart’s goal on the hour, Wales rescued a draw through a Simon Church penalty in the 89th minute.
Like Northern Ireland, Wales are also now beginning their build-up to UEFA EURO 2016, and Isgrove hopes he can keep in contention for a spot in manager Coleman’s squad.
He added to FA Wales TV: "Me and Danny [Ward] have made our debuts and France is just round the corner. He’s always willing to give a chance, so we’ve just got to come in and impress, work hard on the training ground and take it on into matches."