Ghislain was originally selected as a reserve for the men's 4 × 400 m relay at the 2008 Summer Olympics in Beijing. He was finally named to the national relay team at the start of the heats, when his teammate Kristof Beyens decided to pull out from the competition to focus on his race for the 200 metres. Ghislain set an astonishing national record of 3:00:67, along with his teammates Cedric van Branteghem and twins Kévin and Jonathan Borlée, with a third-place finish in the first heat, giving them a qualifying place for the final round. By the following day, he and his team placed fifth in the finals, with another record-breaking time of 2:59.37.