The 20-year-old stormed to victory with a brilliant personal best time of 49.66sec. in Manchester on Saturday afternoon, having progressed as the fastest qualifier on Friday.
‘It felt amazing. It’s a bit breezy, but to come out here and get the gold is just amazing in a field of really high-class athletes,' Chalmers said.
Fellow Guernseyman Peter Curtis also ran a PB, clocking 52.00sec. in sixth place.