I assume you are referring to the Battle of Dyrrhachium. The new thing was not the cavalry charge with lances (which was a standard practice for the Byzantines as well) but charging with couched lances. That, when combined with specific changes in equipment, made the charge more effective.

In the bigger picture, the Byzantine Empire lost the battle but ultimately won the war. That marked the end of decline for the empire and started the Komnenian restoration, making the Byzantine Empire a major military power for the next century.

The cavalry charge became a lost art, because people learned how to counter it. Even during its heyday, heavy cavalry was vulnerable to feigned retreat tactics, possibly for psychological reasons. Byzantines used it to defeat Normans at Larissa a year after Dyrrhachium, and Mongols later used it effectively in their invasions of Poland and Hungary. And around the time of the Hundred Years' War, infantry had learned how to hold its ground against cavalry charges.