Ciara Mageean smashed Sonia O'Sullivan's 1500m National record and defeated arch rival Laura Muir at Friday's Diamond League meeting in Brussels.
Mageean ran a career best 3.56.63 to just edge Muir of Great Britain, who finished second in a time of 3.56.86.
It was a masterful performance from Mageean who hung back in fourth position until the beginning of the final lap. From that point on the County Down native ate up the ground and powered past Diribe Weltej of Ethiopia.
