Sanmahung made national headlines in 2018 when he became the youngest player to score for Chonburi, doing so for the club's 'B' team in the Thai League 4.[2] For the 2020 season, he was loaned to Thai League 3 side Banbueng, alongside teammate Warakorn Thongbai.
^"จักรพงษ์ แสนมะฮุง แนะทีมต้องปรับเกมรับและเกมรุกให้ดีขึ้น" [Jakkapong Saenmahung suggested that the team need to adjust the defensive game and the offensive game better.]. thfootball.com (in Thai). 18 July 2017. Retrieved 15 October 2022.