Fernando Torres scored the only goal of the game in the 38th minute as Atletico edged Athletic Bilbao 1-0 on Wednesday.
Torres' first-half strike maintained the pressure on title holders Barca, with the two teams level on 79 points, a point more than Atletico collected throughout the 2014-15 campaign as they finished third last term.
"The dressing room is happy," Simeone said via the club's official website.
"Exceeding the numbers of last season with four rounds to go is a very important step with the competition that we have with ourselves and our own requirement to continuously improve ourselves.
"To surpass the numbers of last year makes us happy.
"Regarding the match, we made a great effort. You cannot end up winning without the effort we have made, especially in the second half, where Athletic intensified the pressure more than in the first."
Of Torres, who has now scored in his past five games in all competitions, Simeone added: "The moment he is living is important.
"He is helping the team to continue competing for the best. It was a great play, a great goal and a great finish. This will surely strengthen the team and himself for what’s to come."