Olympic 4x100m gold medallist Darren Campbell suffered defeat at the hands of 18-year-old Craig Pickering at the Bedford International Games.
In a race preceded by four false starts, Milton Keynes' Pickering sped home in 10.36 seconds with Campbell finishing fifth in 10.47s.
Between them were Peto Bangura (Victoria Park and Tower Hamlets), AAA Under-23 champion Tim Abeyie (Woodford Green with Essex Ladies) and Matthew Thomas (Newham and Essex Beagles).
It was the second big 100m race won by Pickering this summer. He clocked 10.22s to win at the Loughborough International last month - and he finished well clear of the high quality Bedford field.
While Pickering will now head for the Norwich Union AAA Under-20 Championships at Bedford in a fortnight's time to seek qualification for the European Junior Championships in Lithuania, Campbell will return to a bout of heavy training ahead of the Norwich Union World Trials and AAA Championships next month in Manchester.
It was also a big day for the youngsters in the GB women's team at next week's European Cup match in Portugal, Yasmine Regis ( Windsor, Slough, Eton and Hounslow).
She achieved the longest triple jump of her career so far, 12.97m, to finish second to Irish record holder Taneisha Scanlon (Shaftesbury Barnet), who reached 13.50m. Both efforts were wind assisted.
Andy Frost (Woodford Green with Essex Ladies), who will be making his Cup debut next week, won the hammer with 69.10m.
Campbell earned some consolation when he eased to victory in the 200m B race in 21.17s - a time that would have had him battling for third place in the A race.
It was won by another 18-year-old, Julian Thomas ( Birchfield Harriers) in 21.04s, the time that was also given to the runner-up, Bedford's own UK Inter-Counties champion at the distance, Graham Beasley (Belgrave Harriers).
Olympic heptathlon bronze medallist Kelly Sotherton (Birchfield Harriers) was second in the 100m hurdles in an encouraging 13.37s.
She finished sevenhundredths behind former world junior champion Julie Pratt (Woodford Green with Essex Ladies). Sotherton also finished fifth in the shot with 12.92m.
Of the athletes preparing to compete for GB in next week's European Cup, Janine Whitlock (Trafford AC) had the most uplifting day.
Despite the blustery wind, she took her UK record to 4.46m, 1cm higher than she cleared at the Loughborough International last month.
Jonathan Moore was relieved to finish third in the triple jump with a leap of 15.95m.
More importantly the 21-year Birchfield Harrier emerged unscathed on the runway where he ruptured his patella and almost ended his career three years ago this month.
Moore admitted to being " both apprehensive and frightened on my first round jump but I am pleased to have got this competition out of the way.
"I jumped within five centimetres of the qualifying distance for the European Under 23 Championships, which is one of my goals for this season."
Amy Harris, the 17-yearold Commonwealth Youth long jump champion jumped nine centimetres further than ever before, winning the women's event with 6.28m.
Her Birchfield Harriers clubmate Leigh Smith completed a club double winning the men's competition by one centimetre with a windassisted 7.57m leap.
A week after his Great Britain debut in Glasgow Tom Parsons was runner-up in the high jump with 2.18me.
The Commonwealth long jump champion, Nathan Morgan won in Geneva on Saturday with a legal jump of 8m.