In fact, Porto was able to beat Arsenal in the first leg thanks to their far more experience playing in the UCL than Arsenal. So it is not surprising if Porto can overcome a team as strong as Arsenal in the first leg. But I am also confident that Arsenal will eventually progress to the next stage. Because Arsenal has also recently had an increase in goal productivity. And Arsenal have also strengthened their defense more recently. Even in the match against Brentford, we could actually see Arsenal almost completely controlling the match. And Brentford even they continue to struggle to get out of the pressure. It's just that Brentford's defense is also very solid. So Arsenal were having quite a difficult time. But in the end Arsenal still won. I am sure that in the Arsenal vs Porto match there will be more than 2 goals and I hope Arsenal will score 3 goals. This seems excessive but we'll see whether Arteta's troops can be relied on at home or not.
First leg, FC Porto make us surprised after defeating Arsenal had impressive performance in premier League with teams most scoring goals every match. Unfortunately Arsenal can't make any attempt or shot on target when facing FC Porto on the first leg match and had to losses over 1-0. I think have difference level competition between domestic league and Champion League, with impressive performance in domestic league and current performance from Arsenal very quit well can't guarantee with their opportunity in Champion League on second leg match for winning above two goals.
FC Porto will totally full defensive on second leg match, leaded over 1-0 on first leg seems enough to make hold draw the second legs match result and securing the quarter final ticket.