[2] In 2019, he won the World Open Under-16 Snooker Championships, defeating Hungarian Bulcsú Révész 4–2 in the final.

[6] In January 2023, Kowalski defeated Mateusz Baranowski 5-2 in the final of the Polish Championship in Lublin.

[9] In March 2024, he reached the final of the EBSA European Under-21 Snooker Championships where he lost to Liam Davies.

[10] He entered Q School in May 2024 and in the second event he progressed to the latter stages with wins over Jed Mann, and former professional James Cahill.

[11] In the final round he faced Englishman Simon Blackwell and triumphed 4-1 to earn an assured two-year card on the World Snooker Tour.