Genk won the game 5-2 and Ünal opened the scoring with a well timed header to open his scoring account at the Belgium Pro League outfit.
The 18-year-old striker was delighted with his first goal and shared a picture on Instagram scoring and celebrating the moment alongside the caption: “This is my first official goal for Genk, keep fighting together!”
Ünal joined City on a £2 million transfer from Bursaspor over the summer but was forced to move abroad on loan due to not getting hold of the necessary work visa requirements.
The Turkish international striker joined Genk on a two-year loan but City have the option to call him back after his first season.
The young striker has played 127 minutes of first-team football for Genk in the Jupiler Pro League this season.
Ünal is rated as one of the brightest prospects in Turkish football and currently holds the record as being the youngest player to have ever scored in the Super League aged just 16 against Galatasaray in 2013.