After turning professional in 2009, Forsström spent his formative years on the satellite Nordic Golf League. Made his breakthrough on that Tour in 2015 when he won once and finished as a runner-up three times to seal a place on the Challenge Tour the following season.

Enjoyed a successful rookie campaign on the Challenge Tour, when he won the KPMG Trophy in Belgium after carding four rounds in the 60s - which included an eagle on the 17th hole in the final round.

Spent seven consecutive seasons attempting to graduate from the Challenge Tour, but finally earned playing privileges on the DP World Tour for 2023 after winning Qualifying School Final Stage.

Won his maiden DP World Tour title later that season, claiming a one-stroke victory over fellow Swede Jens Dantorp at the Soudal Open – his second win on Belgian soil.