Atletico won the second leg after Radamel Falcao scored in the 89th minute ending Hannover's unbeaten home run in European competitions.
The German side were participating in only their second European campaign in their history and with Mame Diouf levelling the scores after an Adrian Lopez strike in the 81st minute, they held out hope for a second goal forcing the match into extra time.
But luckily for Simeone's men, it did not materialise and they now face the prospect of Valencia in the semi-finals of the competition. The first leg will take place on April 19 at the Vicente del Calderon.
Simeone was proud to see his reach team the semi-final stage for the second time in three seasons and he believes that Atletico can now be considered as a major force in European football. He was also keen to laud the strikeforce of Lopez and Falcao explaining that the two have settled in well at the club and so have been productive up front.
"Today is important because many fans will be happy with Atletico," he told reporters after the game.
"We are among the best in Europe and we feel good."
"There is little to say about Falcao and Adrian. They are players who feel at home."
Lopez added to the positive words by his manager by stating that Atleti are keen to do their best to ensure that they succeed in the competition.
"We have tremendous enthusiasm for the Europa League," he revealed.
Falcao added, "We're happy with the win. It was for all fans who gave us their support and indeed encouraged us, in both the good and the bad times!"