Iwan Thomas gave an early-season warning to his rivals in Britain's biggest track event of Olympic year.
The 6ft 2in Welshman raced to fourth in the all-time United Kingdom 400 metres rankings with a 44.66sec victory at a meeting in Johannesburg.
Only British record holder David Grindley (44.47), now-retired Derek Redmond (44.50) and Roger Black (44.59) have run faster.
Thomas, who was handicapped by a hamstring injury last season when his best was 45.58, said: "I'm hoping to win at least a relay spot for the Games. To make one of our three places in the individual event, I know I will have to be running under 45 seconds."
Alongside Thomas, Black and Grindley, the contenders include European champion Du'aine Ladejo, European Cup winner Mark Richardson, European junior title holder Mark Hylton and fast-improving Jamie Baulch.
Black, a former double European champion, said: "If everyone stays healthy, the Olympic trial race should be something special."Reuse content