WATCH: Federer denied entry at locker room in Oz

It turns out that even a 20-time Grand Slam champion has to follow the rules. Roger Federer was caught without his credential outside of the locker room at the Australian Open and the security guard didn't let him pass.

The exchange was caught on hallway cameras, and show Federer having to wait a few moments for his physio Daniel Troxler to come to the rescue. Everyone from the media and ground staff to ballpersons and players are expected to have their credentials hanging around their necks at all times, but you'd think the guard would still let the two-time defending champion walk in.

Two years ago, Rafael Nadal made the same mistake at the Paris Masters event, and the security guard let him through but not before asking who he was.

Needless to say both moments picked up plenty of viral internet action.

The hallway cameras in Melbourne have caught both fun and private moments that don't normally get showcased on TV, like Nadal congratulating Federer on his third-round win.

Federer will face Stefanos Tsitsipas in the fourth round, while Nadal will play Tomas Berdych.

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