Mageean competes in the European Youth Olympics later this month
Ciara Mageean chopped more than two seconds off her personal best time in finishing second in the 800m final at the World Youth Championships.
The Portaferry girl clocked a time of 2:03.07 to come in behind Kenyan runner Cherono Koech, who recorded 2:01.67 in Sudtirol in Italy on Sunday.
Mageean improved on her own Irish junior national record.
The 17-year-old becomes the first NI athlete to win a medal at an IAAF outdoor world championships.
Paul McKee won an indoor world bronze in the 400m at the 2003 championships in Birmingham.
Mageean returns home on Monday but will be heading to Finland for the European Youth Olympics on Friday, where she will run the 1500m.
The local teenager, ranked fourth in the world, won her semi-final and set the fastest time of the final qualifiers in Italy.