After last week's underwhelming performance against Japan, the head coach challenged his Ireland squad to step up their performance.
Ireland responded immediately.
Ireland had faded late against the All Blacks and required most of the match to get going versus their Asian opponents.
Nevertheless, against the Wallabies, they began strongly, with the talented back shining brightest during a comprehensive triumph that marked the team's best performance of the season.
In his first test match start at full-back, the player scored a hat-trick, contested brilliantly for high balls and played exceptionally against the nation of his origin.
"Look, I've experienced a pretty challenging period with fitness issues honestly," Hansen stated.
"I longed for being in this squad, I understand there's considerable discussion about me not exactly being born here and I wasn't raised here, but I love this team and this seems like home.
"Whenever I have to represent for the national team it's a privilege, if you don't put in a performance you might not receive that opportunity again.
"My entire focus this period was to take the field and do what I could do."
Coach declared: 'Excellent athletes require no excuses'
Following 28 caps on the flank, the player was entrusted the number 15 position for the first time with several players unavailable.
In his case, it was simply a case of picking up where he left off during the warmer months.
The experienced player had been in excellent form before injury disrupted his dream of joining the Test squad.
Having come back last month, he suffered a lower body injury that ruled him out for earlier fixtures.
The coach had indicated that the player was particularly motivated and these proved not empty words as the ex- provincial player gave his coach a welcome selection dilemma for upcoming games.
"So my initial reaction were, 'You better perform excellently in those different colored shoes!'," said Farrell, referring to the player's decision to sport mismatched boots.
"Actually I believed that was fitting but apparently Hansen just made that personally anyway. So he's attracted attention to himself before he's even started.
"I told to him before the match, 'Good players don't need excuses, they can perform and just play naturally, you can get the man of the match if you want,' and he went, 'Yeah, I concur.'
"Therefore he's that type of player, he prepares thoroughly, he's got a excellent attitude to get across his detail and so that's why he fitted right into the team and he was able to perform naturally because of that."
The player's performance also earned praise from the rival manager, who stated he was the "standout opposition performer" on the evening.
"In my view he was outstanding, his knowledge was evident to the fore," commented the former international coach.
"Regrettably, Mack was likely the best Australian player on the pitch. He's has a great ability and he's such a good competitor."
Pressed about what makes Hansen a good fit at full-back, Farrell continued: "Showing up in the middle of the field is something that he does from the flank anyway, but I imagine he's better in place for that frequently.
"The player's aerial play was brilliant, wasn't it? I believed we didn't get bored of doing the correct approach and that was putting the possession back on them to secure territory.
"The reason that was the correct strategy to do is because it's the likes of Mackie who was getting the possessions returned, and other teammates, so [it's] quite satisfying."
Beyond Hansen, there were multiple encouraging aspects for the coach.
Another player was excellent on his return to the number 10 position, the set piece and throw-in operated smoothly and different teammate did not appear out of place in his first appearance in the forwards.
But perhaps most satisfying for the manager was the team bookending the match with two strong spells.
Hansen's initial two tries occurred in the first 11 moments while other teammates scored in the final stages after the other team had scored, ensuring the home side concluded on a positive note.
"In my opinion we truly let ourselves go and attacked the game straight from the beginning," stated the coach.
"The way we handled various elements throughout the match, especially the opposition responding just before half-time and reorganizing ourselves and giving a display like we achieved in the second half, I believed as far as territory and being familiar with the majority of our game in that later period was truly satisfying."
The strength of South Africa are awaiting for Ireland, in what might be considered as an unofficial conclusion to the previous season's drawn two-Test contest on rival soil.
The coach's side will need to reach a higher standard to beat the consecutive title holders, but Saturday's defeat of the Australian team was a important step in the correct path after an uninspiring start to their autumn schedule.
