Has there ever been a 8–1 in the Primeira Liga?

Yes, 2 times.

The first time: August 31, 2009, SL Benfica beat Vitória de Setúbal (SL Benfica 8–1 Vitória de Setúbal).

The last time: May 5, 2019, Sporting CP beat Belenenses (Belenenses 1–8 Sporting CP), 7 years ago.

Home wins: 1. Away wins: 1.

Nearby scores

1. 9–0 Never
2. 9–1 Never
3. 9–2 Never
4. 8–0 1 time
5. 8–1 2 times
6. 8–2 Never
7. 7–0 9 times
8. 7–1 5 times
9. 7–2 1 time

All games

1. May 5, 2019 Belenenses 1–8 Sporting CP
2. August 31, 2009 SL Benfica 8–1 Vitória de Setúbal