by Alex Hoad

Adam Gemili rounded-off his debut season in full-time athletics in fine style, smashing his 200m PB to become the fastest man in Britain for three years.

The 18-year-old Dartford phenom was running for his club Blackheath & Bromley Harriers in the National Junior League Final at Derby on Sunday when he won the 200m in 20.38, taking 0.15secs off his personal best, set only two weeks before in the Diamond League at Birmingham.

The only Brit to have run faster as an under-20 was Christian Malcolm (20.29) 14 years ago. Gemili has another year as a junior to break the Welshman’s record.

The last Brit to run quicker was Toby Sandeman in 2009 (20.37)

Gemili only began full-time training at the start of the year and only improved his 200m PB from 20.98 - run in the same meeting in Derby last year - to 20.70 in April.

The former Dartford Grammar School pupil also won the 100m at Derby in 10.21s - well below his PB of 10.05 set in Barcelona in July when he won the World Junior Championships - and even ran a leg of the 4x400m to help his team.

His rapid rate of progress saw his 100m PB at 10.23 until his breakthrough performances at Regensburg, Germany, on June 2, when he ran 10.11 and then 10.08 in one afternoon.

He went on to miss a place in the Olympic final in London by just 0.04 seconds after finishing third in his semi-final.

Gemili has run the five fastest times by any under-20 in the world this year, 0.12 faster than anyone else.