"I never dreamed that I could be going for my own stage victory in a race like the Giro d'Italia, so this is a great moment," he said.
"I can't be too disappointed, but when you go that close, you always wish you're on that top step.
"I was waiting for the sprint because I thought I had a good chance but then when Pirazzi got away, I waited for someone else to chase and perhaps feed off that. It was just a little bit too late."
On a stage like this one, where all of the general classification contenders are looking for a peaceful day before three crucial stages, just getting into the breakaway is a victory in itself. McCarthy made it in with 25 others, and there was never a chance of the peloton chasing them down.
"It was a really hard start to the stage and when the big group took off, nearly every team was in there, so I was one of the last guys to get across with Gasparotto of Astana."
"You get a bit excited at times in situations like that but I had Bjarne [Riis] in my ear via the radio, telling to me take it easy and eat and drink. Evgeni Petrov, my teammate was to attack on the last climb, while I was to feed off that and follow the moves. Fortunately on the descent I went with Pirazzi and De Gendt on the run-in to the finish. We worked pretty well together until the finish."
McCarthy turned professional with Bjarne Riis' team in 2013 and earned his spot in the Giro d'Italia with some consistent riding and hard work for the team. He is currently 97th in the overall classification, indicating he been able to handle three weeks of racing and is likely to complete his first Grand Tour in Trieste on Sunday.
"I've hopefully got plenty more years to come in my career and so I'll keep trying," he said.
"The Giro has been a great experience for me. We've put in a huge effort to help Rafal Majka for the GC, I've tried to help him before the final climbs. I've also been able to learn from the older guys and as my first Grand Tour it's been a great experience. I'll be really happy with what I can take away from this."