'Our glorification and glamorisation of alcohol in this country is normalised to the point where we can't even celebrate success without booze on live TV. It's bizarre,' he wrote in a scathing tweet.
'Imagine if this was in Canada and the broadcaster hoisted a joint onto their new champion?'
Mathison's controversial take sparked heated debate online.
'Looks like Ash quite enjoyed her beer. It was her best friend who offered it,' wrote one woman.
'Didn't look or feel awkward to me, it's a celebration after all,' added another.
Another said the moment was 'a bit cringe' but suggested it was a good example of being able to "have a beer and 'drink responsibly".
"This is true and a good point," Matthison replied.
"I think I was trying to highlight how booze, which has enormous health, economic and family impacts get lionised yet all other 'drugs', many less harmful are maligned."
Tennis lovers were much less critical of Barty, taking to social media to praise her for enjoying a hard-earned drink with her close friends.
