The French champions began the defence of their Ligue 1 title with a 1-0 win at Lille on Friday in a match that proved to be far from straightforward.
With Zlatan Ibrahimovic injured and new recruit Di Maria watching from the stands, Laurent Blanc's men lost Adrien Rabiot to a senseless second yellow card inside the opening half-hour.
However, an impressive goal from Lucas Moura in the 57th minute secured a valuable three points for PSG and their first opening day win since 2010.
Pastore is hoping the result will be a sign of things to come and thinks the arrival of Di Maria from Manchester United has given everyone associated with the club a big boost.
"It is the first time since I joined PSG that we won the first game of the season," he told Canal Plus. "We got the three points and we have to keep doing it this way.
"With Di Maria here it will be hard to be in the starting XI but it is good news for the club. He is a fantastic player and I think he can bring many things to the team.
"We hope that he will give us those little things we missed in the years before to help us move past the quarter-final of the Champions League."
Pastore only featured for the first 45 minutes of the match due to him lacking in fitness following his Copa America efforts with Argentina earlier this summer.
