On 18 October 2020, Geoghegan Hart won his first stage of a Grand Tour, taking stage 15 of the Giro d'Italia on the Alpine summit finish of the Piancavallo. Following in the steps of previous winners Marco Pantani and Mikel Landa, Geoghegan Hart rode away from the remaining peloton with the Sunweb duo of Jai Hindley and Wilco Kelderman, out-sprinting Kelderman at the line to take the stage win. The result also took Geoghegan Hart up to 4th in the General Classification of the race ahead of the second rest day.
