It was the first time McColgan's front-running had yielded the ultimate prize. In the Seoul Olympics she gradually ground down the opposition until, into the last kilometre, there was only Olga Bondarenko left. It was one runner too many: Bondarenko sprinted away over the last 200 metres to deny McColgan victory.
Four years on, McColgan has the advantage of experience. One experience was childbirth, which physiologists believe is strengthening - although McColgan is sceptical. She was back at the highest level within four months, under the guidance of her husband Peter, and nine weeks after Tokyo recorded the fastest-ever marathon debut when she won in New York.
With this sort of strength, her vulnerability to kick finishers is reduced, but still exists. It is hard to see many staying the pace, but it would take only one to stage an upset. The South African Meyer has plausible credentials to do so. Long in Zola Budd's shadow, she has achieved world-leading performances at 5,000m over the past two years. On her pre-Olympic European tour she ran 14min 51 sec, 10 seconds faster than McColgan two days later.
McColgan is the champion, and there are many pretenders. Derartu Tulu, the Ethiopian who tracked her for three-quarters of the world championship race, is faster this year. Last year's field in Tokyo included Kathrin Ullrich and Uta Pippig, with 5,000m bests comparable to McColgan's, and a fast finish. Lynn Jennings, world cross country champion and possessor of a fearsome kick, was also there.
That they and others could not live with McColgan's pace was not only because of her relentless 75sec lapping, but because it was their second race in three days (in Barcelona heats and final are six days apart). McColgan's strength allowed her to take them in her stride; for Meyer, Barcelona will be a big step into the unknown.