Richard Goodman, 18, trimmed his 1,500m PB to 3:45.66 in the qualifying round at the Aviva Senior World Trials in Birmingham.
His performance demonstrated his renewed confidence and raised him to fourth in the UK Under 20 rankings for the distance.
Goodman said: "Although, as the fastest non-qualifier, I just missed out on the final, I wasn't disappointed at all in my performance. My previous fast races have been time trials, but this one was tactical.
"No-one wanted to make the early pace and I went through two laps in a slow 2:04. The race hotted up considerably and my last 800 was timed at 1:56.
"The conditions were perfect and the atmosphere in the packed stadium gave me a real boost. It was excellent preparation for my 3,000m at this weekend's Diamond League at Crystal Palace."
Jessica Hurley of Potters Bar sliced 11 seconds from her 800 metres PB, recording 2:40.94 in the Young Athletes League at Hendon.
Eleven-year-old Hurley, who takes up a sports scholarship at Queenswood School in September, is following in family footsteps. Her mother Colette (nee Kaufman) had a best time of 2:08.6 and competed in the trials for the Barcelona Olympics.
Nathaniel Lane allowed himself just two days' recovery from his second-place finish in the Welsh 10,000m Championships before recording 8:50.42 for 3,000m in a British Milers Club race at Exeter.