"It was a good victory for us. It was difficult because we did not play as well as we did against Manchester United at the weekend but it was important to start with a win in this competition," said Mascherano.
"Marseille played really well and had their fans behind them and it is never easy away from home, especially in the Champions League.
"But I will repeat that the most important thing was the result because the victory means that we have made a good start which we will now look to build upon.
"We are happy with the result. Marseille have some very good attacking players who play well between the lines and they made life difficult for us.
"We couldn't control their best players as much as we would have liked but Stevie made the difference for us.
"Stevie is a winner and when you have a player like him you have to enjoy it and allow him to take responsibility.
"It is really good for us to have a player like him because you can play with confidence with him alongside you.
"He is a truly special player and there are not many players who can do so many good things for their team and score the kind of goals he scores."