OLI Bromby missed out on this evening's IAAF World Under-20 100 metres final by the most agonising of margins - falling short by just one thousandth of a second.

The Southampton AC sprinter did club and country proud by running a huge personal best of 10.37 seconds in the second of three semi-final heats in Bydgoszcz, Poland.

He blasted away to his best ever start and at the 90-metre mark was a clear second, but he just missed out on the dip to Brazilian Derick Silva to finish third.

It was a legal run with a following wind of a mere 0.2 metres per second and, at that point, good enough to get Bromby through to the final as a fastest loser.

However, just five minutes later, Bromby’s Great Britain teammate Rechmial Miller of Hercules Wimbledon also finished third in the third and final semi with an identical 10.37 time.

Miller, though, had the benefit of a stronger tailwind of 0.7 mps and, with the officials taking thousandths of a second into account (about five millimetres at sprinting speed), it was Miller who came out marginally faster – 10.367 seconds to Bromby’s 10.368 – to go through.

Frustratingly for Miller, a World Youth bronze medallist, he suffered a painful attack of cramp in the final and trailed home last in 16.18 seconds.

The USA’s Noah Lyles, winner of Bromby’s semi-final, claimed the title in 10.17.

Despite the disappointment of missing out on the final, Bromby’s coaches Gary and Sara MacDonald Gray could not have been prouder of their 18-year-old protégé who exceeded all expectations.

“It was a bittersweet experience for Oli,” reflected Gary. “The satisfaction of running a personal best on the biggest stage of all for junior athletes being tempered by the disappointment of knowing that even a modest gust of wind would have meant taking his place in the final.

“Sara and I, along with his club, are incredibly proud of the way Oli conducted himself and look forward to Oli and Miller combining with fellow Brits Cameron Tindle and Ryan Gorman as they shoot for a sprint relay medal later in the week.”