Herne Hill Harriers' Saskia Millard made a staggering breakthrough on Saturday, as the 13-year-old became the all-time fastest U15 girl in Surrey over 800m.
Millard ran two minutes 8.21 seconds in a mixed-gender race at the London Inter Club Challenge at Barnet Copthall, having never previously breached 2:12.
The time not only makes Millard the quickest U15 girl in Surrey athletics history, it was also the third fastest by a 13-year-old in the UK.
The time was inevitably a Harriers age-category club record and saw her rise to third in the all-time list of first claim Herne Hill runners - a list headed by 20-year-old Katie Snowden's 2:03.46.
Millard's time is all the more remarkable as her previous best was 2:12.9, set in a UK Youth Development League fixture at Reading in May.
Meanwhile, Snowden, who Millard may one day hope to emulate, had a frustrating day at the weekend's British Championships in Birmingham.
Snowden ran well in her 800m heat, clocking 2:04.50, but was never able to quite get on terms with the three ahead of her - internationals Alison Leonard, Jessica Judd and Emily Dudgeon, and her fourth place time was not fast enough to qualify for the final.
Aisha Naibe-Wey proved to be Harriers' outstanding performer in Birmingham, where she improved her 400m hurdles personal best and club record by a couple of hundredths of a second in clocking 58.48 for second place in her heat.
Naibe-Wey finished outside the medals in fifth in 59.12. Gavin Johnson-Assoon matched Naibe-Wey's finishing position, as he finished fifth in the javelin.
Johnson-Assoon's best throw of 65.59m did, however, place him third Englishman, winning him a bronze medal in the English Championships (which were held as part of the British event).
Herne Hill's four sprinters, Marvin Popoola, Byron Robinson, Chris Pope and Dwayne Dowding, found the 100m heats tough and were unable to produce their regular times, while Jessie Knight was sixth in a hard heat of the women's 400m in 54.98.
Nicholas Atwell and Peter Phillips did very well to make the 400m semi finals, but failed to make the final after clocking 48.39 and 48.49 respectively.
Lastly, Lewis Lloyd soon found he had not recovered from a week of illness and had to drop out after 800m of his 1500m heat.
Mohammed Ismail was 10th in 16.09 and Jack Hillier 14th in 16.21.
The club's leading parkrun performers included Ismail (second at Brockwell Park in 16.52, Jonathan Ratcliffe (fifth at Dulwich in 17.51), and Robert Edwards (first at Peckham Rye in 17.53).
Louis Waterman-Evans was part of the winning male team of three to five members at the Endure 24-hour race on Wimbledon Common.