Aussie tennis supporter takes umpire's chair

An Australian tennis supporter has taken it upon himself to make the biggest calls in tennis after climbing into the umpire's chair at the US Open.

Wearing the unmistakeable green and gold, the man, reportedly a part of the famous supporters’ touring group, 'the Fanatics', stormed an abandoned court, took his place in the chair and began announcing a phantom match.

However, the man's calls interrupted the adjoining courts where Americans Rajeev Ram and Ryan Harrison were duelling in their first round match.

Despite their initial security slip, US Open officials were quick to bring the man down from the best seat in the house as a crowd, drawn to the court by the commotion, began applauding his efforts.

It is not known whether the supporter was reprimanded for his incursion onto the court.