Robben, 36, decided to rejoin his boyhood club in June where he started his career in 2000.
In a preseason friendly against Arminia Bielefeld on Sunday, the winger scored in his first home appearance since his return.
Robben, who captained Groningen, opened the scoring after 17 minutes in typical fashion, bending the ball into the bottom corner from outside of the box with his left foot. The match finished in a 1-1 draw.
It was Robben's first goal for the club since 2002, with that strike coming at their former ground -- Oosterpark stadium.
"Yes it has been a while," he told the club's website. "It is always nice. I have looked forward to the first moment in our stadium.
"And obviously you want it to be full but these are the circumstances now. But yes, it is just nice."
Robben's former club Bayern Munich praised him for the goal and when asked about their social media post, he replied: "It is not something that you get rid off, such a finish.
"It was not the most important thing of today, scoring a goal. I am just happy to progress, to play 45 minutes. A few good moment in the match where you feel you're OK. but there is still room for improvement."
Robben will look to feature in his first competitive match next Sunday when Groningen host PSV Eindhoven in the league.
Groningen were in ninth position in the table before the 2019-20 campaign was cancelled due to the coronavirus pandemic in April.