Dartford sprinter Adam Gemili became only the sixth British man to rocket to a sub-10 second 100 metres in Birmingham yesterday (June 7) before a set of pyrotechnics threatened to bring his season crashing down.

Gemili, of Blackheath and Bromley Harriers, toppled onto the track as he crossed the finish line in the process of recording a personal best 9.97s behind American winner Marvin Bracy.

The 21-year-old later confirmed he had injured his right hamstring, which could threaten his participation in the World Championships in Beijing in August.

Gemili, who left the Alexander Stadium track in a wheelchair, told former world championship medallist Darren Campbell he had been startled by a set of flame-shooters which burst into action as the athletes crossed the finish line.

Campbell, at the event in his role as a commentator for BBC Radio Five Live, said: "Adam told me he got a shock by the pyrotechnics going off at the end when he was stretchered off.

"It's madness. You can't manufacture atmosphere."

But organisers insisted there was nothing new about the pyrotechnics, with an event spokesman saying: "(They) are a standard part of Diamond League Event presentation and have been since the series first launched.

"We have had no complaints about their use at this or any other events."

Gemili, who attended Dartford Grammar School, said: "I felt my hamstring go as I dipped but I'm in good spirits.

"I can't make a comment on the injury yet.

"Not the fairy-tale ending I wanted, but I'm proud to be the only Brit to go sub-10 and sub-20.

"British sprinting is really stepping up and I'm glad to be a part of it."