St Lawrence's debut at an international athletics competition was at the 2008 World Cross Country Championships where he competed in the senior men's race; finishing 126th in at time 39minutes and twoseconds. He then competed at the 2010 Commonwealth Games and finished 7th in both the 5,000metres and the 10,000metres. At the 2011 World Championships St Lawrence competed in the 5000metres and finished 11th in his heat and therefore did not progress to the final. Also in 2011 was the World Cross Country Championships where St Lawrence finished 60th, 66 places better than his previous World Cross Country Championships. For the 2012 Summer Olympics, St Lawrence qualified for the 10,000metres on the first day of the qualification window. At the Olympics, he finished 20th in his race. St Lawrence's next major competition was the 2013 World Championships where he competed in both the 5,000metres and the 10,000metres. In the 5,000metres he finished 18th in his heat and didn't progress to the final and in the 10,000metres he reached the final before withdrawing. He competed in his 2nd Commonwealth Games in the 2014 edition. He reached the final of the 10,000metres and finished 16th. St Lawrence qualified for the 10,000metres for the 2016 Summer Olympics in May 2015 at the athletics track in Palo Alto, California; the same track on which he qualified for the 2012 Olympics.