The American secured a 6-4, 6-3 win over Medvedev, making a fine start to his second appearance at the season-concluding tournament. Fritz capitalised on an error-filled first set from the Russian, during which he hit seven double faults.
The third seed clinched a 6-3, 4-6, 7-6(6) win over the American to confirm his progression from Green Group. Coming into the match after a win over Canada's Felix Auger-Aliassime, Ruud managed to hold his calm to clinch the semifinal spot after a tense battle of two-hours and 12 minutes
Fritz completed a dream debut at the season finale while smashing Nadal's bid to win the lone big title that has eluded him in his legendary career with a 7-6(3), 6-1 victory.