Dai Greene beats Williams in British Championships final
Dai Greene beat Welsh rival Rhys Williams in the final of the 400 metres hurdles in the on Saturday in 48.66 seconds.
But Williams ran a personal best 48.85s in Birmingham to secure World Championship selection after briefly seeming to lead the final.
Brett Morse also ensured a World Championship discus place with a winning 62.05m first-round throw.
Wales' Lee Doran took the javelin title with a 70.77m fourth-round throw.
In the 800m, Gareth Warburton finished third in 1:49.62 with fellow Welshmen Joe Thomas seventh in 1:49.62 and Joe Maynard eighth and last in 1:50.69.
As reigning world champion, Swansea Harrier Greene was already guaranteed the chance to defend his title in Moscow on 10-18 August.
Greene competed at the trials in a bid to run himself into form after a torrid season so far.
Williams had handed Greene his first defeat by a fellow Briton in five years on this track at the Diamond League meeting 12 days ago.