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

Yes, 5 times.

The first time: September 8, 1946, Guadalajara beat San Sebastián (Guadalajara 8–1 San Sebastián).

The last time: October 21, 1994, América beat Correcaminos UAT (América 8–1 Correcaminos UAT), 32 years ago.

Home wins: 5. Away wins: 0.

Nearby scores

1. 9–0 2 times
2. 9–1 1 time
3. 9–2 6 times
4. 8–0 7 times
5. 8–1 5 times
6. 8–2 11 times
7. 7–0 23 times
8. 7–1 22 times
9. 7–2 17 times

All games

1. October 21, 1994 América 8–1 Correcaminos UAT
2. May 3, 1987 Puebla 8–1 Tampico Madero
3. March 18, 1979 Pumas UNAM 8–1 Tampico
4. October 30, 1949 Veracruz 8–1 Marte
5. September 8, 1946 Guadalajara 8–1 San Sebastián