| 1. Ronde | 14.08.2020 | NK Opatija | - | Hajduk Split II | 2:1 | ||||
| 2. Ronde | 22.08.2020 | NK Sesvete | - | NK Opatija | 0:1 | ||||
| 4. Ronde | 12.09.2020 | NK Rudeš | - | NK Opatija | 1:2 |  |
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| 5. Ronde | 15.09.2020 | NK Opatija | - | HNK Cibalia | 0:1 | ||||
| 6. Ronde | 19.09.2020 | NK Dubrava | - | NK Opatija | 1:4 |  |
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| 12. Ronde | 30.10.2020 | NK Međimurje | - | NK Opatija | 3:0 | ||||
| 13. Ronde | 25.11.2020 | NK Opatija | - | NK Inter Zaprešić | 3:2 | ||||
| 19. Ronde | 20.02.2021 | NK Opatija | - | NK Sesvete | 1:0 | ||||
| 22. Ronde | 14.03.2021 | HNK Cibalia | - | NK Opatija | 2:0 | ||||
| 26. Ronde | 17.04.2021 | NK Osijek II | - | NK Opatija | 1:0 | ||||
| 27. Ronde | 21.04.2021 | NK Opatija | - | NK Junak Sinj | 1:0 | ||||
| 28. Ronde | 24.04.2021 | NK Dugopolje | - | NK Opatija | 0:0 | ||||
| 25. Ronde | 28.04.2021 | NK Opatija | - | Hrvatski Dragovoljac | 0:0 | ||||
| 29. Ronde | 01.05.2021 | NK Opatija | - | NK Međimurje | 1:1 | |
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| 30. Ronde | 07.05.2021 | NK Inter Zaprešić | - | NK Opatija | 3:0 | ||||
| 34. Ronde | 29.05.2021 | NK Opatija | - | NK BSK Bijelo Brdo | 2:2 |
Kroatië