 Portugal: Lisbon - Doubles - Main |
|---|
| 1/8-finals | Faria J./Faria L. | Sijsling I./Smits G. | 2:0 (6:4, 6:3) | dettagli | 29.09.2021 |
 Czech Republic: Prague 3 - Doubles - Main |
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| 1/8-finals | Fallert F./Johnson H. | Sijsling I./Smits G. | 2:1 (6:1, 2:6, 10:4) | dettagli | 25.08.2021 |
| Czech Republic: Prague 2 - Doubles - Main |
|---|
| 1/8-finals | Karlovskiy E./Tiurnev E. | Sijsling I./Smits G. | 2:0 (6:3, 7:5) | dettagli | 11.08.2021 |
 Germany: Braunschweig - Doubles - Main |
|---|
| Semi-finals | Sabanov I./Sabanov M. | Sijsling I./Smits G. | 2:0 (6:1, 6:2) | dettagli | 09.07.2021 |
| Quarter-finals | Hidalgo D./Martos Gornes S. | Sijsling I./Smits G. | 1:2 (6:4, 3:6, 8:10) | dettagli | 08.07.2021 |
| 1/8-finals | Gabashvili T./Kadhe A. | Sijsling I./Smits G. | 0:2 (4:6, 5:7) | dettagli | 06.07.2021 |
 Italy: Forli - Doubles - Main |
|---|
| 1/8-finals | Lenz J./Moraing M. | Sijsling I./Smits G. | 2:1 (4:6, 7:62, 10:1) | dettagli | 15.06.2021 |
 Russia: St. Petersburg 2 - Doubles - Main |
|---|
| Quarter-finals | Sijsling I./Smits G. | Kravchuk K./Yevseyev D. | 0:2 (2:6, 4:6) | dettagli | 11.03.2021 |
| 1/8-finals | Gabashvili T./Nedovyesov A. | Sijsling I./Smits G. | 1:2 (1:6, 6:3, 4:10) | dettagli | 10.03.2021 |
 France: Cherbourg - Doubles - Main |
|---|
| Quarter-finals | Sijsling I./Smits G. | Klein L./Molcan A. | 0:2 (64:7, 69:7) | dettagli | 11.02.2021 |
| 1/8-finals | Drzewiecki K./Jebavy R. | Sijsling I./Smits G. | 1:2 (6:1, 64:7, 7:10) | dettagli | 09.02.2021 |
| France: M15+H Bressuire - Doubles - Main |
|---|
| 1/8-finals | De Schepper K./Napolitano S. | Sijsling I./Smits G. | 2:1 (7:64, 62:7, 10:5) | dettagli | 19.01.2021 |
 Turkey: M15 Antalya - Doubles - Main |
|---|
| Semi-finals | Sijsling I./Smits G. | Harris B./Sabanin Y. | 1:2 (6:0, 3:6, 13:15) | dettagli | 09.01.2021 |
| Quarter-finals | Sijsling I./Smits G. | Deschamps A./Savelev D. | 2:0 (6:2, 7:5) | dettagli | 09.01.2021 |
| 1/8-finals | Sijsling I./Smits G. | Fils A./Koshis C. | 2:0 (6:4, 6:2) | dettagli | 07.01.2021 |
| France: M25+H Rodez - Doubles - Main |
|---|
| Final | Doumbia S./Reboul F. | Sijsling I./Smits G. | 2:0 (6:3, 7:5) | dettagli | 16.10.2020 |
| Semi-finals | Arribage T./Broville M. | Sijsling I./Smits G. | 0:2 (63:7, 60:7) | dettagli | 15.10.2020 |
| Quarter-finals | Sijsling I./Smits G. | Added D./Eysseric J. | 2:0 (6:4, 6:2) | dettagli | 14.10.2020 |
| 1/8-finals | Sijsling I./Smits G. | Virtanen O./Wenger D. | 2:0 (6:3, 6:1) | dettagli | 13.10.2020 |
| France: M25+H Plaisir - Doubles - Main |
|---|
| Quarter-finals | Clezar G./Sakamoto P. | Sijsling I./Smits G. | 2:0 (6:3, 7:66) | dettagli | 16.09.2020 |
| 1/8-finals | Sijsling I./Smits G. | Fomba L./Valsecchi P. | 2:0 (6:2, 6:2) | dettagli | 15.09.2020 |
 Austria: M25 Vogau - Doubles - Main |
|---|
| 1/8-finals | Guinard M./Haerteis J. | Sijsling I./Smits G. | 2:0 (6:2, 6:3) | dettagli | 18.08.2020 |
 Slovenia: Portoroz - Doubles - Main |
|---|
| Quarter-finals | Sijsling I./Smits G. | Miedler L./Weissborn S. | 0:2 (2:6, 4:6) | dettagli | 15.08.2019 |
| 1/8-finals | Sijsling I./Smits G. | Golubev A./Vavassori A. | 2:1 (66:7, 7:5, 10:7) | dettagli | 14.08.2019 |
