The Greek fifth seed will face Germany's Alexander Zverev for a place in Sunday's final. Tsitsipas has the most wins on the ATP tour this season (38) and won clay court titles at Monte Carlo and Lyon.
Medvedev, the 2019 US Open runner-up and this year's Australian Open finalist, suffered his first quarter-final loss at a major. He had never won a match at Roland Garros before this tournament.
