In fact Atletico Madrid's strength this season is still the same as last season, but they are often unable to consistently maintain the team's performance so we often see the Atletico Madrid team playing below standard in the domestic league and Atletico Madrid's victory over Inter Milan was a bit of a surprise because Inter Milan was in conditions are very good this season but this is the Champions League, there are many surprises and a mentality is needed and Atletico Madrid have proven that they have a pretty good mentality on the Champions League stage.
Inter Milan defeat from Atletico was indeed surprising, because statistically Inzaghi squad recorded a better performance, Inter Milan failed to maintain the lead they got in the first leg. It is true that Atletico managed to prove that anything is still possible, they have a strong mentality in turning things around. Even though in La Liga Diego Simeone squad is less stable, in the Champions League they have managed to perform otherwise, their reputation in the Champions League cannot be underestimated. Inzaghi was certainly very disappointed with this defeat, their unbeaten journey in the Champions League this season was stopped in the round of 16 through a penalty shootout.
On the other hand, I see Atletico having greater luck, because they are playing at home. That doesn't mean Inter Milan is completely bad, they have tried their best to progress like last season. The Champions League cannot be predicted, the top team could lose surprisingly. We will see how far Atletico can go this season, if they get tough opponents in the quarter finals like Madrid, Man City or Bayern Munchen, they will most likely be eliminated.