On this day (23 January) in 1926 Manchester United were defeated 6-1 at Old Trafford by managerless Manchester City. This remains the record score in a Manchester derby match (equalled of course during Mancini’s time as manager of Manchester City).
More on the game for subscribers here:
Sadly, highlights of that game are not known to have survived, but here’s the first All-Manchester FA Cup semi-final played between the two teams that same season:
https://www.britishpathe.com/video/an-all-lancashire-cup-final/
I doubt there’s anyone alive who was at either of these Manchester derbies, though I am aware of fans who would have been young children at tbis time. If you were there please get in touch, or if you were why at the later 6-1 City victory at Old Trafford then why not leave your memory as a comment or email it to me for possible future use on this website?