Has there ever been a 11–0 in all competitions?

Yes, 5 times.

The first time: May 16, 1897, Flores Athletic beat Palermo Athletic (Flores Athletic 11–0 Palermo Athletic) · Primera Argentina.

The last time: December 1, 1968, Vélez Sarsfield beat Huracán (Bahía Blanca) (Vélez Sarsfield 11–0 Huracán (Bahía Blanca)) · Primera Argentina, 57 years ago.

Home wins: 5. Away wins: 0.

Nearby scores

1. 12–0 7 times
2. 12–1 3 times
3. 11–0 5 times
4. 11–1 6 times
5. 10–0 25 times
6. 10–1 21 times

All games

1. December 1, 1968 Vélez Sarsfield 11–0 Huracán (Bahía Blanca) · Primera Argentina
2. January 7, 1967 Borussia Mönchengladbach 11–0 FC Schalke 04 · Bundesliga
3. August 18, 1912 Quilmes 11–0 San Isidro · Primera Argentina
4. August 26, 1906 Reformer 11–0 Barracas Athletic · Primera Argentina
5. May 16, 1897 Flores Athletic 11–0 Palermo Athletic · Primera Argentina