Having a narrow lead of one goal in the first leg is still not necessarily safe for FC Porto in the second leg which they will play tomorrow. Because Arsenal is also a quite dangerous team when playing in the Champions League with the motivation of being the host, FC Porto still has to try to score a goal in the second leg even though they also have to make a fairly good defensive strategy because if the lead is still very small, of course FC Porto themselves must be aware that they still need to fight hard at home to Arsenal.
Correct. One goal ahead of Arsenal does not guarantee that Porto is safe, of course this second leg match will be the biggest test for Porto to defend their back line so as not to concede because of course Arsenal will appear to attack from the start.
Moreover, Arsenal is currently on a trend of 4 consecutive wins at home, all of which occurred in the domestic league. From these 4 wins, Arsenal managed to score 14 goals and only conceded 3 goals. So overall this season Arsenal have played 18 home games. Arsenal achieved 14 wins, 2 draws and 2 defeats.
Of course, these statistics mean that Porto will come under a lot of pressure from Arsenal, they will not easily escape at Arsenal's home ground. So my prediction in the second leg of the last 16 of the UCL League will be Arsenal's struggle to overturn the aggregate, the match will be won by Arsenal with a score of 3-1.