The 26-year-old Ghanaian winger, who joined Manchester City from Bournemouth in January for around 65 million pounds, produced one of the most audacious finishes seen in a Wembley final, improvising a backheel flick from Erling Haaland's cross in the 72nd minute that clipped the post and nestled into the far corner beyond Robert Sanchez.
Semenyo was lost for words when reflecting on the moment afterwards.
"It feels surreal to be honest. I don't even have words to describe it. It happened a couple of times in training. It happened perfectly today. The ball was behind me, as long as I got contact on it and it was towards goal, I was hoping it would go in. Everything happened so fast. I wanted to get into the box and make sure I'm a presence. It came straight to me and I just had to improvise as quickly as I can."
The FA Cup is his second major honour since moving to the Etihad, having already won the Carabao Cup in March. He acknowledged just how unfamiliar the experience of competing for trophies still feels.
"As a kid I always wanted to play for the top teams, competing for trophies and shining. I'm grateful. I just had to keep working hard and you get your chance. I've never competed for trophies like this before. Everything is new to me."
Named player of the match, Semenyo added that Guardiola had given him one instruction on arrival — to stay exactly as he is.
City trail Arsenal by two points in the Premier League with two games remaining. Semenyo's first fixture after the final is a return to his former club Bournemouth on Tuesday, and he was clear that celebrations would have to wait.
"I don't think there will be much celebrating tonight. It's about getting ready for Tuesday. Hopefully results fall in our hands."