After two years training in Amsterdam, Netherlands under Ernesto Hoost, Slowinski moved back to Adelaide in 2009 and began to teach and train out of Rikers Gym. He has competed in the K-1 and SUPERKOMBAT promotions. He started kickboxing in 1998 under Alan Wong.
He turned pro on February 2001.
He faced Cătălin Moroşanu at the K-1 World Grand Prix 2012 in Tokyo Final 16 on 14 October 2012 and lost via unanimous decision after visiting the canvas twice in round three. He defeated Nato Lauui via unanimous decision at Kings of Kombat 8 in Melbourne on 8 December 2012.
Slowinski and Ben Edwards met for the fourth time on 23 March 2013 in Canberra, Australia at Capital Punishment 7. He made his professional Mobile Marketing Association debut against Leamy Tato at Mobile Marketing Association Downunder 4, on 21 September 2013.
The event was held at the Adelaide Arena in Adelaide, South Australia.
He spend time training for this bout with the Blackzilians training camp in Boca Raton, Florida. He lost to Raul Cătinaș by third round KO at the SUPERKOMBAT World Grand Prix 2013 Final in Galați, Romania on 21 December 2013.