All four goals came from different sources, Steph Catley and Caitlin Foord finding the back of the net inside the opening half an hour before Kyah Simon, in her 50th international appearance and Michelle Heyman struck within a minute of each other early in the second half.
After a period of dominance, the Matildas broke the deadlock in the 17th minute when Catley unleashed a cracking drive into the top corner. Foord then slotted home clinically to double the lead after a fine build up.
Foord almost had a second on the stroke of half time only for the Vietnam goalkeeper to pull off a superb save from close range.
But in the space of 60 seconds soon after the resumption for the second half, Simon found space in the penalty area to score and then Heyman pounced on a mistake by the Vietnam 'keeper to put the ball into an empty net.
"Today was another step in the process, it was good to get another hit out under our belts not only to get more match time but an indication of the things we still need to work on," Matildas coach Alen Stajcic said.
"While there was some good football in patches, the next three weeks is vital for making sure we're ready for our first match of the World Cup against the USA on June 8."
The two teams will meet again on Thursday night at Jubilee Oval in Kogarah in the Matildas' official farewell match before the squad departs for Canada on Saturday.
Australia 4 (Catley 17’, Foord 29’, Simon 47’, Heyman 48’) defeated Vietnam 0
Australia: Lydia Williams (gk) (Melissa Barbieri (gk)), Larissa Crummer (Lisa De Vanna), Clare Polkinghorne (c), Servet Uzunlar (Hayley Raso 61’), Steph Catley (Elise Kellond-Knight 46’), Caitlin Foord (Ashleigh Sykes), Alanna Kennedy, Teresa Polias, Kyah Simon, Nicola Bolger, Michelle Heyman (Leena Khamis 61’)
Unused substitutes: Mackenzie Arnold (gk), Tameka Butt, Laura Alleway, Katrina Gorry, Emily van Egmond, Samantha Kerr
