 Ẹ parí gbólóhùn tó wà nísàlẹ yìí: : 2013 World Junior Championships ní Dubai, Horton gba àmì ẹyẹ wúrà márùn-ún àti fàdákà kan. O gba ife-eye 200 m, 400 m, 800 m ati 1500 m freestyle ati pelu Luke Percy, Regan Leong ati Blake Jones gba ife-eye 4 × 100 m freestyle relay gbogbo won ni akoko igbasilẹ tuntun. Ẹgbẹ ti Horton, Leong, Isaac Jones ati Jack McLoughlin pari keji lẹhin awọn ara ilu Gẹẹsi ni iṣẹlẹ 4 × 200 m freestyle relay. 