John McEnroe savages loudmouth Australian Open fan

American tennis legend John McEnroe was well-known for his infamous on-court histrionics during his playing career, and now tennis fan has copped his wrath.

McEnroe was on the Nine panel along with Todd Woodbridge previewing the men's semi-final between Novak Djokovic and Lucas Pouille when a fan behind the set yelled out McEnroe's infamous line of "you can not be serious".

The seven-time Grand Slam winner then returned serve in spectacular fashion, cutting off the conversation about the semi-final.

"Hold on one second before I interrupt," McEnroe said.

"After six times it gets a little old."

McEnroe's call-out was well-received by the crowd behind the panel who burst into laughter along with his fellow panellists Rebecca Maddern and Todd Woodbridge.