Adelaide United advanced to the quarter-finals with a big 3-0 win over rivals Melbourne Victory at Marden Sports Complex. 

However, the biggest talking point from the match was Regan's robust challenge on Austin in the first half. 

The Victory winger was in full speed down the left, with Regan blocking his path and standing his ground, resulting in a hard-hitting shoulder hit on Austin. 

It left the 26-year-old on the ground for minutes while his Victory team-mates wanted to see a card handed to Regan. 

Fox Sports put up a clip of the challenge with the caption "You won't see a better hit all season", with Austin replying after the game "It's a great hit until someone breaks their f***ing neck.. I'm ok btw thanks for asking". 

The tweet has since been deleted. 

The challenge has caused plenty of debate on social media, with Fox commentator Mark Bosnich saying Regan "should've been sent off". He continued: "That's a problem with (the) game here if people think that's ok."

However, on the other side of the debate, Socceroo Trent Sainsbury said there was "nothing wrong with that hit" and that Austin running with his head down was the problem.