1st(1st leg) SD Formentera - CD Alavés 1:3 (0:1)
2nd (2nd leg) CD Alavés - SD Formentera 2:0 (0:0)
1st(1st leg): 03/01/2018 18:00 2nd (2nd leg): 10/01/2018 18:30 Winner: CD Alavés
1st(1st leg) Lleida Esportiu - Atlético Madrid 0:4 (0:2)
2nd (2nd leg) Atlético Madrid - Lleida Esportiu 3:0 (0:0)
1st(1st leg): 03/01/2018 18:00 2nd (2nd leg): 09/01/2018 18:30 Winner: Atlético Madrid
1st(1st leg) Cádiz CF - Sevilla FC 0:2 (0:2)
2nd (2nd leg) Sevilla FC - Cádiz CF 2:1 (1:0)
1st(1st leg): 03/01/2018 20:00 2nd (2nd leg): 11/01/2018 18:30 Winner: Sevilla FC
1st(1st leg) UD Las Palmas - Valencia CF 1:1 (1:0)
2nd (2nd leg) Valencia CF - UD Las Palmas 4:0 (1:0)
1st(1st leg): 03/01/2018 20:00 2nd (2nd leg): 09/01/2018 20:30 Winner: Valencia CF
1st(1st leg) RC Celta - FC Barcelona 1:1 (1:1)
2nd (2nd leg) FC Barcelona - RC Celta 5:0 (4:0)
1st(1st leg): 04/01/2018 18:00 2nd (2nd leg): 11/01/2018 20:30 Winner: FC Barcelona
1st(1st leg) CD Leganés - Villarreal CF 1:0 (0:0)
2nd (2nd leg) Villarreal CF - CD Leganés 2:1 (0:1)
1st(1st leg): 04/01/2018 18:00 2nd (2nd leg): 10/01/2018 18:30 Winner: CD Leganés
1st(1st leg) CD Numancia - Real Madrid 0:3 (0:1)
2nd (2nd leg) Real Madrid - CD Numancia 2:2 (1:1)
1st(1st leg): 04/01/2018 20:00 2nd (2nd leg): 10/01/2018 20:30 Winner: Real Madrid
1st(1st leg) Espanyol Barcelona - Levante UD 1:2 (1:1)
2nd (2nd leg) Levante UD - Espanyol Barcelona 0:2 (0:2)
1st(1st leg): 04/01/2018 20:00 2nd (2nd leg): 11/01/2018 18:30 Winner: Espanyol Barcelona