Ku dhammaystiro weedha soo socota: Ciyaaraha Olombikada Tokyo 2020, Duncan wuxuu ku guuleystay lacag 200m qaab xor ah, isagoo dhameystiray 0.04 ilbiriqsi oo ka dambeeya guuleystaha iyo saaxiibkiis, Tom Dean. Wuxuu ku raacay dahab isagoo qayb ka ah kooxda 4 × 200m freestyle relay oo ay weheliyaan Tom Dean, James Guy, iyo Matt Richards, isagoo ku guuleystay rikoor Yurub ah 6 daqiiqo 58.58 ilbiriqsi. Waxa kale oo uu ku guuleystay billad lacag ah tartanka ragga ee 200 mitir, iyo mid kale oo tartanka ragga ah.
4 × 100 mitir oo isku dhafan oo ay la socdaan Luke Greenbank, Adam Peaty, iyo James Guy, isaga oo ka dhigaya ciyaartooygii ugu horreeyay ee Ingiriisi ah ee ku guuleysta afar billadood hal Ciyaar oo keentay inuu ku baaqo in loo magacaabo darajo.