The versatile Argentine was happy with his side's performance versus Los Blancos, and is determined to finish the job in the second leg
The Argentina international feels they could have won the game by a bigger margin, but was happy to see the Blaugrana stick to their own footballing philosophy in the first leg of the tie.
"Beyond the result, we were the ones that controlled the game and that's important. We have to maintain our identity and be ourselves," Mascherano was quoted as saying on the Barca website.
"Seeing what we did on the pitch it is a bit of a shame that we only won 3-2, but we're happy with the final result. I believe that we did a good job. We won and that's what we wanted to do.
"We can't forget that we won and that we beat a great team, now it's up to us to go there and win the title."
The return takes place at the Santiago Bernabeu on Wednesday, August 29.