Rio 2016: Is this the moment Justin Gatlin realised he should not have eased up?

The 34-year-old American failed to qualify for Friday's men's 200m final after appearing to slow down before the line

Gatlin looks back across the field at his opponents before the line (Getty)

Justin Gatlin failed to qualify for Thursday’s men’s 200m final after appearing to ease up during the final 50m of his semi-final heat.

The 34-year-old sprinter finished third, behind Panama’s Alonso Edward and the Netherlands’ Churandy Martina, with a time of 20.13 seconds.

Yohan Blake, who won silver in the men’s 200m at London 2012 with the event’s fastest-ever losing time of 19.44 seconds, finished sixth.

Gatlin’s time was not enough to secure one of two ‘best loser’ places, which went to Great Britain’s Adam Gemili and Turkey’s Ramil Guliyev.

Images of the race showed Gatlin looking back across the line at his opponents after he had appeared to ease up prematurely.

The American, a two-time drug cheat who divides opinion within athletics, reportedly blamed a tightening of his ankle for the error.

Gatlin’s long-standing rival Usain Bolt cruised through the field in his semi-final heat to qualify for Thursday’s final.

Bolt himself appeared to ease up before the finish line after establishing an early lead and was almost caught by Canada’s Andre De Grasse.

The Jamaican, who hopes to complete an Olympic 'triple triple' in Rio, shared a joke with De Grasse as they crossed the line.