Competing at her first Olympic Games at the age of 21, Diane Borg carried the flag of Malta at the closing ceremony. She qualified for the London Games as a wildcard entrant, because her fastest time of 11.89 seconds, set at the 2011 Games of the Small States of Europe, was 0.51 seconds slower than the "B" qualifying standard for the women's 100 metres. She stated that it was "a great feeling" that she would be representing Malta and every person hoping that she would perform well. Borg took part in the event's second heat on 3 August, finishing third out of eight entrants, with a time of 12 seconds. Her finishing position allowed her to advance to the first round as the slowest qualifier. Borg was drawn in the second heat of the first round, held on the same day, placing eighth (and last) of all competitors, with a time of 11.92 seconds. She finished 53rd out of 78 runners overall, and was unable to advance to the semi-finals because her time was 0.57 seconds slower than the slowest athlete who progressed to the next stage.