Gambin had ascended to prominence in the international scene at the 2008 European Championships in Eindhoven, Netherlands, competing as a member of the Maltese squad. There, he finished thirtieth in the men's 100 m butterfly with a time of 54.33 seconds to clear a FINA B-cut and earn a place on his first ever Olympic team. Leading up to the Games, Gambin continued to set four more national records in some of his specialty events at Luxembourg Open, and three more at the Paris EDF Open.