The Grammy award-winning singer gave the staff member a telling-off after she spotted him telling audience members to sit down.
In footage posted on social media, Adele is seen finishing her single 'Water Under The Bridge' before telling the man: "Excuse me sir? I know you work here but could you stop telling people to sit down? This is a music show."
"If people can't see then they stand up," she continued. "If you're moaning about people dancing, what the f*** have you come to a show for? If I see one more person be told to sit down, I swear to God."
A fan wrote: "Adele's Melbourne show is already off to a kick-arse start with a super sweet same-sex marriage proposal."
"That wasn't planned... I had no idea," Adele said.
Another fan urged Australian Prime Minister Malcolm Turnbull to "take note", as same-sex marriage is currently illegal in Australia.
Earlier in the evening, Adele had joked that if her audience was looking for a good time they were at the wrong place, as her concert was "basically just two hours of crying and songs about my ex-boyfriend."