Porto vs Arsenal 1-0. Arsenal as a whole dominated the game but Porto's very strong defense made it difficult for Arsenal to score goals.
And Porto's 1 goal in the remaining extra time scored by Galeno in the 90+4 minute was a painful goal for Arsenal.
Napoli vs Barcelona 1-1 and Barcelona's goal was scored by Lewandowski in the 60th minute, and Napoli's goal was scored by Osimhen in the 75th minute.
I think Arsenal have nothing to worry about, they dominated the entire match only to concede a goal in the final minutes. But in the second leg in London I'm sure they will be able to overturn the result of the first leg.
as for Napoli, I saw a team trying to get back on track, it's not easy to get satisfactory results when you change manager every two months, getting a draw against Barcelona was an excellent result and they can hope to make the breakthrough luck on the way back