This time around the fastest man in the world did not go missing. In his first race since winning his fight to avoid a ban for three whereabouts tests Christian Coleman glided to victory in his 100m heat in 9.98sec, despite easing down to a trot, to show why he is a prohibitive favourite for gold at these world championships in Doha.

That made the American the fastest qualifier, with Zharnel Hughes looking the best of the Britons in winning his heat in 10.07sec, although Adam Gemili and Ojie Edoburun will also be in the semi-finals, which take place on Saturday along with the final.

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Not everyone wants Coleman here. Indeed the track and field legend Michael Johnson went as far as to tell the BBC on Friday that his compatriot does not deserve to be the face of the sport because he needs to take more care not to miss drugs tests.

However, the IAAF president, Sebastian Coe, insisted Johnson was wrong. “We have to be very careful not to play fast and loose with the reputation of athletes,” he said. “I am glad they reviewed his case, it’s a grown up sensible approach, I am pleased Coleman is here and I want to make sure he is given every opportunity to be one of the faces of these championships.”

Coleman was in no mood to expend any unnecessary energy afterwards. “It feels great,” he said, when reporters tried to question him. A request for a BBC interview was met with cold eyes and a shake of the head.

Meanwhile there was disappointment for Britain’s Lynsey Sharp as she crashed out of the women’s 800m heats. The Scot had been quietly fancied to do well in the absence of three DSD athletes, including the reigning champion Caster Semenya, yet she could finish only fifth in her heat in 2:03:57. However Sheleyna Oskan-Clark and Alexandra Bell made it through to semi-finals. Morgan Lake did not live up to expectations as she failed to qualify for the high jump final after clearing only 1.85m, well below her personal best.

But the biggest surprise of the day was seeing the 18-year-old Jakob Ingebrigtsen, the favourite for the men’s 5,000m, disqualified, having appeared to ease into the final, after the British team noticed he had stepped inside the rail during the heats.

It is an extraordinary harsh rule in general and the Norwegian is appealing against the decision. But whatever the judges’ decision, Britain’s Andrew Butchart will be through to the final as a fastest loser after initially missing out. In the same race Guinea-Bissau’s Braima Dabo produced a heart-warming display of sportsmanship as he helped an exhausted Jonathan Busby of Aruba across the line. Busby finished in Dabo’s arms to huge cheers at the Khalifa International Stadium before collapsing to the track.

The runner needed medical attention after finishing the race – thanks to the help of Dabo in the final 300m – and was eventually taken away in a wheelchair.

Dabo sacrificed his own race but still ran a personal best of 18 minutes 10.87 seconds, although Busby was disqualified.