The Northern Italian urban infantry seem to have made something of a habit out of giving knights a bloody nose (as in, "from running headfirst into a wall").

Not that the Anglo-Saxon infantry militia appears to have had tremendous problems holding the Norman cavalry at bay at Hastings, either.

Actually, if knights really were able to plow aside everything, one has to wonder at the standard Medieval practice of using heavy infantry spearmen as a solid fallback/reform base for the cavalry, and for shielding your own knights while they switched to their proper warhorses from the riding horses they normally rode ("got on their high horses", as they saying goes)...

Or how for example Middle Eastern cavalry, once the novelty of the massed couched-lance charge wore off, could readily enough take knights head on and not get pulverized.