The Red and Whites came from behind to secure the victory thanks to goals from Hirving Lozano, Gaston Pereiro and Marco van Ginkel, with the result also going some way to making up for their early exit from this season's Europa League.
Cocu was certainly pleased with his side's display and he believes it is always important to kick-off the new league season with a victory.
"It was a spectacular game and it's nice to start the new season with three points," the 46-year-old told the club's website.
The former Dutch international is now hoping to take the positives from that victory into the rest of the season, although he is aware his side are still far from the finished article.
"I think we did pretty well today," he added. "Of course there is room for improvement but we will take the positives into the next game."