The 1500-metre runner went in the first of three heats with the first six qualifying automatically. Cronje, surprise bronze medallist from the previous world championships in Moscow 2013, held back from the start as the pace was slow on the first two laps in the extreme heat with the temperature around the 30 degree mark.
On the final lap, the runners clicked into gear and it turned out to be a sprint for the line to find out who would go through. Cronje did well to grab the sixth and final qualifying spot in a time of 3 minutes 43.29 seconds.
Fellow South African Dumisane Hlaselo lined up in the second 1500m heat, and though he managed a faster time than Cronje he would fall out of the competition. In a much faster race the South African managed ninth place in a time of 3:40.25 – which was just under a second outside the qualifying time for the semi-finals.