Kearney's enthusiasm after arriving as a first-half replacement for Gordon D'Arcy was one of the few highlights to emerge from a challenging afternoon at Croke Park.
And while he sympathises with D'Arcy's misfortune - the Lions centre will miss the rest of the 6 Nations with a fractured forearm - he intends to seize his opportunity.
Ireland name their team to face France on Tuesday and 21-year-old Kearney, who has two caps, has trained his sights on starting against the champions.
"With Gordon being a close friend it's hard to take what happened to him - it's not something you want to see," he said.
"But it's gave me a chance which is fantastic. It was good to get on the pitch quite early in the game.
"Personally I thought the match was fantastic. It was the first time I've played in that arena and it was something pretty special.
"I'll never forget it. Collectively we got the win which was the most important thing and we created opportunities, which was a positive.
"We left a few of them behind but hopefully we'll be more ruthless against France.
"Selection has opened up for me a bit now but there's nothing definitive there as some of the Ireland A boys played well against England on Friday."
Italy's perseverance troubled Ireland who began to buckle once prop Martin Castrogiovanni barged over for a 63rd-minute try.
It was hardly the performance coach Eddie O'Sullivan had demanded to draw a line through the World Cup, but Kearney insists the changing room was buoyant afterwards.
"There was nothing down about the mood following the game. It wasn't easy against Italy and we had to dig deep to come out on top," he said.
"Obviously there's a bit of frustration because of the opportunities we left behind but we know they're little things that can be easily fixed.
"Making a winning start was the most important thing. It's no secret that Ireland aren't playing to their full potential but against France we'll be looking to prove what we're capable of."