US teenager Sydney McLaughlin smashed the world U18 best for 400m hurdles when running 54.46 on the final day of the New Balance National High School Championships in Greensboro, North Carolina, on Sunday (19).
McLaughlin's run took almost a second off the previous record of 55.20, held by US compatriot Leslie Maxie since 1984. It was also a US U20 record, breaking Lashinda Demus's mark of 54.70.
The 16-year-old from New Jersey routed the field, coming home well clear of Anna Cockrell, who ran 56.28 for second.
The run also moved McLaughlin up to fifth in the world on the 2016 senior list. The world lead is currently held by USA's Shamier Little at 53.51, which she ran to win at the NCAA Championships last week.
Last year, McLaughlin shot to prominence internationally when taking the gold medal in the girls' 400m hurdles at the IAAF World Youth Championships Cali 2015 and this year she has continued her progress, lowering her 400m best to 51.84 indoors in New York in March.
On Friday, McLaughlin also anchored her Union Catholic school to victory in the sprint medley relay, moving from last to first on the final 400m leg and clocking a split of 50.93.
She will next compete at the US Junior Championships next weekend in Clovis, California, before turning her attention to next month's US Olympic trials in Eugene.
Cathal Dennehy for the IAAF