Has there ever been a 10–3 in the Liga MX?

Yes, 1 time.

The only time: August 19, 1945, Atlante beat Tampico (Tampico 3–10 Atlante).

Nearby scores

1. 11–2 Never
2. 11–3 1 time
3. 11–4 Never
4. 10–2 1 time
5. 10–3 1 time
6. 10–4 1 time
7. 9–2 6 times
8. 9–3 2 times
9. 9–4 Never