[9] On 29 April 2018, Obeng made his competitive debut for Hearts starting in a 1–0 match against fierce rivals Kumasi Asante Kotoko.
He got the chance to only play three matches as the league was cancelled due to the Anas Number 12 expose which caused the dissolution of the Ghana Football Association.
[1] The following season, during the 2019 GFA Committee Special Competition, Obeng became a constant member of the starting line up under the management of Kim Grant.
[11] On 14 April 2019, he scored another goal to help Hearts secure a win over Liberty Professionals and keep them on track of qualifying for the CAF Champions League.
Obeng won the Ghanaian FA Cup on 8 August, after Hearts scored Ashanti Gold in the final via a penalty shootout due to goalless draw in extra time.
[23] On 5 March 2023, Obeng played the entire 90 minutes of the 2023 President's Cup, which Hearts won by 1–0, thanks to a header by Konadu Yiadom.