Gilroy became the youngest player to win 100 caps for Ulster when he lined up against the Italians at Kingspan Stadium on Friday night in the GUINNESS PRO12.
During the first-half, it looked like it would prove to be a fruitless night for the 23-year-old as both he and his Ulster teammates struggled to find their rhythm - Mike Allen the only try scorer for a 10-0 lead.
But Ulster - who move up to second in the GUINNESS PRO12 table following the win - clicked into gear in the second 40, running in a further five tries, including a double for Ireland international Gilroy, for a 43-3 victory.
Gilroy's first wrapped up the try bonus point for Ulster while he had the final word with an intercepted effort in the closing minutes to make it six tries after previous scores by Stuart McCloskey and Andrew Warwick as well as a penalty try.
And while accepting his side had taken their time to click into top gear, Gilroy admitted it had been a night to remember.
"It was very enjoyable and a proud moment to get to 100 caps," he told the Belfast Telegraph.
"I didn't think it would have come round as as quickly as it did. And to be honest I was a wee bit nervous going into it.
"I don't really get nervous any more but I got a bit nervous just looking back.
"My first cap felt like yesterday and I was really glad that this happened at home.
"I was delighted to be starting as well. Yes, we faffed about a bit at the start but we ran in some very nice scores at the end there."
Gilroy's double took him to five GUINESS PRO12 tries for the season while he has appeared in 73 games in the league in total, although the Irishman was eyeing up plenty more.
"My first was very special away to Cardiff and I remember a lot of European games as well and really good memories as well. Long may they continue," he added.
"I was looking at the shirt and took an extra few minutes before I put it on.
"And I count myself very lucky to play for Ulster let alone run out for my 100th time."
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