Does knowing how to speak two Romance languages help in understanding a third one?

I am a native Spanish speaker currently studying Brazilian Portuguese on my own for almost a year through TV, films, YouTube videos and Google translate. At this point I can understand 90% of what is said in BR Portuguese and I can speak the language at a decent conversational level with minimal accent. The other day I was with my uncle who recently came from Europe and speaks Italian in addition to Spanish and English. We were watching TV in the Brazilian network Globo for a while and he was able to understand over 80% of what Brazilians were saying on TV and would occasionally laugh. At times, he would pick up on this I wouldn't, all of this without studying Portuguese a day in his life.

I was very surprised on his ease of understanding a language that, although very similar to Spanish, most Spanish speakers have difficulty in understanding and only pick up about 40-50% of what is being said.

Is it possible his knowledge of Italian, combined with Spanish made it much easier for him to understand Portuguese from Brazil than a person who knows only Spanish? Are there words in Italian that are more similar in Portuguese than in Spanish? Anyone with any knowledge of this please let me know.