Muscles quickly twitch and, in a flash of sinew and claw, the video cuts to black as the phone goes underwater.
Muffled sounds of combat are heard before the kangaroo is seen again, seemingly unbothered but without his canine prey.
The man laughs and the camera briefly shows his dog safe on the riverbank.
“Martial arts for everyone even kangaroos,” the caption underneath the video reads, before adding the qualifier: “FYI, BJJ (Brazilian Jiu Jitsu) ineffective in the rover against 7ft tall kangaroos.”
“I’d fight a kangaroo for my dog too,” one person wrote under the video, while another joked that kangaroos are “just deers that have been to prison”.
Warning: Offensive language
The encounter is the latest example of the ongoing feud between dog lovers and kangaroos in the Lucky Country.
In 2018, Daniel Tuohey was left cut and bruised but managed to save his dogs from a rampaging roo and even avoided spilling his beer.
Tuohey’s daughter Bree filmed the incident and told 9News that, although the family can laugh about it now, they were shaken by it at the time.
“I was just hoping that it didn’t go any further than what it did, I was a bit shocked, it was very scary, I’m not sure what I would have done if it had have kept going,” she said.