Photo: Pražský ilustrovaný zpravodaj/Wikimedia Commons, public domain
On August 2, 1924, Czechoslovak Radio (then broadcasting under the name Radiojournal) attempted its first live sports report of a highly anticipated boxing match between Harry Knight (Rocky) representing the US and František Růžička (Frank Rose) of Czechoslovakia.
The commentator watching the match on Letná Plain used a nearby telephone booth from which he reported what was going on to someone in the broadcasting tent in Kbely, where his words were written down and read by a radio announcer.
See more here.