The 23-year-old from Namibia had appeared just four times for the Warriors in the PRO12 in an injury-hit season before the trip to Italy.
But in only his second full game of the season - the other coming in the reverse fixture in September - McGuigan crossed the whitewash twice to lift Glasgow up to second.
And the former Scotland 7s flyer is desperate to stay in the thoughts of head coach Gregor Townsend.
"This time of the year tests all the teams strength and depth and we know we are in good shape in that area," McGuigan told the Evening Times.
"We have some big games over the next few weeks and the guys who are starting those games know it's a good time to make the jersey their own.
"It's been pretty frustrating for me this season as I've been injured and not really had the chance to show what I can do, so to have started on Sunday and got two scores was great.
"We knew that if we cut out the mistakes we'd be in with a very good chance of seeing them off. They scored early on from an interception and a charge down but after that they only managed a couple more penalties.
"We knew if we stuck to our guns, and the game plan, we would win the game."
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