Frenchman Arthur Fils, the No 7 seed, advanced to the quarter-finals of the Swiss Indoors in Basel after defeating Spaniard Pedro Martinez Portero 7-5, 6-3.
Seeded No 20, Fils will now face Greek Stefanos Tsitsipas, the No 3 seed.
Prior to this win, the 20-year-old Frenchman also secured a victory against German qualifier Daniel Altmaier (7-6 (5), 6-3).
In the previous round of the Basel tournament, Martinez Portero, ranked No 39, defeated Jiri Lehecka (6-2, 6-2).
Basel ATP 500, other second-round results (St. Jakobshalle., hard, EUR 2.385.100, most recent results first):
- Felix Auger-Aliassime vs. Giovanni Mpetshi Perricard
- Dominic Stricker vs. Holger Rune
- Denis Shapovalov vs. Roberto Bautista Agut
- Stan Wawrinka vs. Ben Shelton: thursday
- Stefanos Tsitsipas beat Botic van de Zandschulp (Q): 7-6 (3), 7-5
- Andrey Rublev (1) beat Alejandro Tabilo: 7-6 (3), 6-1
- David Goffin (LL) beat Ugo Humbert (5): 3-6, 6-1, 7-6 (7)
