The American clocked 9.76 seconds to lead home defending champion and compatriot Justin Gatlin (9.89) and Canada’s Andre De Graase (9.90).
Britain’s Zharnel Hughes finished sixth in 10.03.
Coleman’s participation was in serious doubt just weeks ago after he was charged with missing three drugs tests in a one-year span, but he insisted – correctly – that his first violation should not count in the 12-month period due to an administration error.
I am a clean athlete, says Hassan
After impressing in the early rounds, the 23-year-old ran a personal best in the final to move sixth on the all-time list and secure his first major outdoor title.
Coleman will be hot favourite to replicate his success at the Tokyo Olympics next summer – the first Games without Usain Bolt since Athens 2004.