ATP - Gstaad 1R start

First round commenced in Gstaad.

2021 Swiss Open Gstaad - an ATP 250 tournament, on Clay, in Gstaad, Switzerland, 19-25 July 2021.

Event not held last year due to COVID-19

2019 champion (not defending):

Albert Ramos-Vinolas who defeated Cedrik-Marcel Stebe 6-3 6-2

The following players withdrew after the main draw was published:

- Yannick Hanfmann, replaced by lucky loser Kacper Zuk due to illness

- Alex Molcan, replaced by lucky loser Enzo Couacaud due to a lower back injury 

First round results:

- Qualifier Vit Kopriva defeated wildcard Johan Nikles 6-2 6-1

- Mikael Ymer defeated lucky loser Enzo Couacaud 4-6 6-3 6-3

- Feliciano Lopez (8) defeated Marc-Andrea Huesler 6-4 4-6 6-5 (retired)

- Benoit Paire (6) defeated Jozef Kovalik 6-3 7-6(2)

- Marc Polmans defeated qualifier Sandro Ehrat 7-5 6-3

- Qualifier Zizou Bergs defeated qualifier Oscar Otte 7-6(3) 6-1