Arthur Fils made it through to the semi-finals of the indoor event in Basel with an impressive 7-6 (7/5), 6-3 win over third seed Stefanos Tsitsipas on Friday. The Russian, however, also had a bad day, beaten by Shelton 7-5, 6-7 (3/7), 6-4 with the American setting up a semi-final showdown for the doubles partners.