On 25 April 2018, Suphanat made his debut against Nakhon Ratchasima becoming the youngest player in the Thai League 1 history that has played in a match at 15 years old and 8 months.

On 9 April 2019, Suphanat became the youngest goalscorer of the AFC Champions League history at 16 years and 8 months against Chinese side, Beijing Guoan.

Earlier that year in June, he had already been training on several occasions at parent club Leicester City, while waiting to receive a work permit.

On 5 June 2019, in a match against rivals, Vietnam, he made his debut at the age of 16 years 10 months, becoming the youngest player in the history of the national team.

During the second leg of the 2024 ASEAN Championship semi-finals against Philippines, Suphanat came off the bench and scored a header in the 116th minute of extra time to send Thailand to the final while suffering with flu.

Suphanat has an older brother, Supachok Sarachat, who is also a footballer and plays as an attacking midfielder for J1 League club, Hokkaido Consadole Sapporo.