It would be an easy 90 minute win for Arsenal. Porto might have a lead over goal but they are no match to what Arsenal is now. The next game is going to be in a much different context as well. Arsenal has placed themselves as the contender for title of the premier league and the match is being hosted in Etihad stadium, the home ground of Arsenal. Arsenal will most probably have a better aggregate than porto during the gameplay and advance to the next round.
Another match on the same day Barcelona vs Napoli would be much competitive one but Barcelona would have a better play.
I agree that Arsenal will be win but it will be not an easy match for them.
In Europe competitions Porto never lost with more than 1 goal difference since Sept 2022.
I guess this match will end with 1-0 or 2-1 in 90 minutes, and the winner will be decided by a penalty shootout.
If Arsenal have a very good chance to win and qualify then yes, Arsenal should be able to win with a score of 2-0 or higher in 90 minutes. Because after all, Arsenal's good trend in the Premier League should also have a good impact on Arsenal's results in the Champion League at this moment but indeed, at the sametime also that Porto is not a weak team and Porto is also not a team that is easily defeated. Therefore, despite Arsenal being the favored team it will still not be easy for Arsenal to beat Porto by a margin of 2 goals. Also about Barcelona, I also believe that Barcelona still has a chance to win compared to Napoli because indeed, Napoli is also still in transition with its new manager. Therefore, Barcelona should be able to take advantage of this factor to be able to beat Napoli in the second leg later.