Mair only reached international level of the sport at age twenty-three and did not compete at a high level in his youth. His first major competition was the 1987 Central American and Caribbean Championships in Athletics and he came away with three medals: bronze medals in the 100 m and 200 m, and a gold medal in the 4×100 metres relay. This marked the beginning of much success with the Jamaican men's relay team. At the 1987 Pan American Games the following month he was eighth in the 200 m final and claimed a bronze medal in the relay, running the anchor leg in a quartet with Ray Stewart, Andrew Smith and Clive Wright. The team regrouped for the 1987 World Championships in Athletics, with Mair leading off this time, and won another bronze medal – the first time that Jamaican men won a relay medal at the competition. Mair made him Olympic debut at the 1988 Seoul Olympics and, after being eliminated in the quarter-finals of the individual 100 m, he joined up with Christopher Faulknor, Greg Meghoo, and Clive Wright for the relay. The team came close to their World Championship medal-winning time in the 4×100 m relay final, but ended in fourth behind the French team who were seven hundredths faster. A double bronze medal win came for Mair at the 1990 Commonwealth Games as the Jamaican men took third in both the 4×100 m relay and 4×400 metres relay. Mair also placed sixth in the semi-finals of the 100 m individually. He was the Jamaican champion over 100 m that year, interrupting a long-running streak of national titles by Ray Stewart. Four years on from his debut year, he returned to the same competitions. He won the highest individual honour of his career at the 1991 Central American and Caribbean Championships in Athletics, taking the 100 m title, and was also a relay silver medallist. The 1991 Pan American Games followed and he placed fifth in the 100 m, but did not take a medal in the relay. The 1991 World Championships in Athletics brought together a team of Dennis Mowatt, Ray Stewart, Michael Green, and Mair on the anchor leg. The group did not reach the heights of four years earlier, but performed well with a time of 38.67 seconds to place sixth in the final. He set a best of 10.18 seconds for the 100 m in Kingston, Jamaica that year – this was a lifetime best and the only time that he ranked in the top thirty globally for the event in his career. He did not compete at the 1992 Summer Olympics. His final international outings were a run in the early rounds of the 200 m at the 1993 IAAF World Indoor Championships, and appearances at the 1994 Commonwealth Games, where he ran in the 100 m heats and was five hundredths short of a relay medal in fourth.
