Megan Penfold won the Lee Valley Under-13/Under-15 Pentathlon on Saturday, posting a total score of 2669.
Penfold, who belongs to Orion Harriers Athletics Club and is trained by Bob Corbett, excelled in all but one event to beat her nearest competitor by nearly 300 points.
In the 60m hurdles, Penfold posted a time of 9.95, just shy of her best time of 9.93 for the year.
The 12 year-old excelled in the field too, jumping 1.50m in the high jump - just two centimetres short of her personal best - and achieving a distance 4.47m in the long jump.
Woodford Green-based Penfold managed 7.82m in the shot put - a distance which meant she equalled her personal best in the discipline.
The only disappointment for the teenager came in the 800m, where she was boxed in at the start of the race.
Despite that setback, Penfold managed to post a time of 2.44, her best time of the year in the event and just two hundredths of a second outside her personal best.