Kubica finished the 11-stage Como event half a minute clear of Felice Re's similar car, despite having to complete the rally with only rear brakes after a minor accident.
The Pole is making a tentative motorsport return in rallying, nearly two years on from suffering horrific injuries in a crash in Italy. He still hopes to rejoin the Formula 1 field eventually.
This weekend Kubica's comeback will step up a gear when he contests the Rallye du Var in France, where his opposition will include experienced former World Rally Championship and Intercontinental Rally Challenge frontrunner Freddy Loix in a Peugeot 307 WRC.
Kubica said Como had allowed him to fully get to grips with the Citroen and that he is now keen to contest increasingly demanding events to test his prowess.
"It's been a good adventure, a fine test ahead of the Rallye du Var," he told Gazzetta dello Sport.
"This rally has been very useful: first of all because it's very demanding, and also because it's allowed me to understand this Citroen almost completely. It's a car with incredible potential.
"I keep my feet on the ground. I need to test myself on the most demanding events.
"I'm a circuit guy, used to fighting for hundredths of seconds. If I'm behind on the road I get angry. However, I have the strength to react and fight until the end. Here Re, [Corrado] Fontana and [Paolo] Porro pushed me hard but in the end I did it.
"I won well, but to be honest I have to say that this Citroen C4 WRC is an exceptional car that will be able to give me more satisfaction, perhaps even bigger than today's."
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