Both coaches do not underestimate each other, so I disagree with that statement. Arteta knows very well the ability of PSG and his coach and he was really serious throughout the match, it's just that the players failed to maximize the goal opportunities from several chances created throughout the match. You can see how Arteta reacts when his players fail to score, it is a form of disappointment that never looks like underestimating his opponent.

Arsenal certainly tried and tried throughout the match, almost managed to equalize, but Merino's goal was ruled offside by VAR. Losing 0-1 at home is certainly not what Arsenal and their manager want, but because the aggregate is not big, there is great hope for Arsenal to make a comeback in the second leg. The problem may be only one, PSG will be playing at home and they will probably give their all there to win the match and qualify for the final. It is still interesting to wait for the drama of the PSG vs Arsenal match in the second leg, but now I am waiting for the Barcelona vs Inter match.