It was really an unbelievable game between Atletico Madrid and Sevilla. I was expecting Atletico Madrid to be comfortable and win this game but I didn't expect such a big score as well.
Atletico was not dominating the game especially for ball possessions but atletico madrid has a very effective attacks compared with sevilla. 
As you can see that atletico had so many shot on target and 75% from the total shot on target can be converted into the goals by atletico's players.
They completely destroyed Sevilla by 6-1. Atletico Madrid had 8 shots on goal and 6 of them ended up with goals. I haven't seen them being this much efficient for a very long time. Depay and Morata were the stars of the day. Morata entered after leaving an hour behind maybe but he still put on a good show also. It was like this was a game for Atletico Madrid to show their best performance and boost their morale by a big percentage.
I think that man of the match is still griezmann. Griezmann's contribution was a lot during the match. Griemmann was always helping to build proper attack. This guy is contributing 1 goal, 1 assist and griezman is also having so many accurate pass and always win in the duel against sevilla's player. Ball possession is true, but Atletico isn't known for possessing the ball in an excessive way like Barcelona or Manchester City. The other statistics are speaking for themselves and as you pointed out, especially the shots on target is what ultimately counts. But what was different this time is the conversion rate of those shots on target into goals. That would be outstanding if that rate was standard for Atletico Madrid.
But as everybody knows that is not the case. They had an extraordinary day yesterday. I was trying to figure out when Atletico Madrid scored six goals for the last time before this, but I couldn't find anything. It probably never happened before! 
Wow Simeone was celebrated yesterday as he broke a record as the coach who has been coaching the Atletico team the most games. It is 613 games now and he became the manager in 2011, which makes this year his 12th year. That is remarkable during these times in soccer.