Following their previous underwhelming performance against the Japanese team, the head coach challenged his Ireland team to improve their game.
The team responded right away.
The Irish side had faded in the final stages against the All Blacks and required considerable time to get going versus Japan.
However, against Australia, they started powerfully, with Mack Hansen excelling brightest during a 46-19 triumph that represented Ireland's finest performance of the season.
Making his first test match appearance at the number 15 position, Hansen registered a three tries, competed brilliantly for high balls and played outstandingly against the country of his origin.
"You know, I've had a pretty challenging run with fitness issues honestly," Hansen commented.
"I missed being in this team, I know there's much talk about me not exactly being raised here and I didn't grow up here, but I adore this group and this feels like home.
"Any time I have to represent for the national team it's a privilege, if you don't put in a good showing you might not get that opportunity again.
"My whole focus this period was to go out and do what I could do."
Manager declared: 'Good players don't need justifications'
After twenty-eight appearances on the flank, the player was entrusted the full-back position for the initial time with several players unavailable.
For him, it was essentially a matter of continuing where he left off during the warmer months.
The experienced player had been in excellent form before physical issues disrupted his aspiration of joining the international team.
Having come back last month, he developed a lower body problem that ruled him out for previous fixtures.
The coach had suggested that the player was particularly determined and these proved not empty words as the ex- club player gave his manager a welcome team headache for future games.
"Well my initial reaction were, 'You need to play excellently in those different colored shoes!'," commented Farrell, referring to Hansen's decision to sport different boots.
"Actually I believed that was fitting but it seems Mack just made that personally anyway. So he's drawn notice to himself before he's even started.
"I told to him before the game, 'Excellent athletes require no excuses, they can perform and just play naturally, you can win the player of the game if you choose,' and he went, 'Yes, I concur.'
"Therefore he's that type of performer, he trains well, he's got a great attitude to get across his preparation and so that's why he slotted right back in and he was able to perform naturally due to that."
Hansen's efforts also received praise from the rival coach, who remarked he was the "exceptional opposition performer" on the evening.
"In my view he was outstanding, his experience was evident to the front," commented the ex- international coach.
"Regrettably, Hansen was likely the best opposition performer on the field. He's has a excellent skillset and he's such a strong competitor."
Pressed about what enables the player a good option at full-back, the coach continued: "Showing up in the middle of the field is a trait that he demonstrates from the flank regardless, but I imagine he's better in place for that more often.
"The player's aerial work was excellent, wasn't it? I believed we didn't get bored of doing the correct approach and that was placing the possession back on them to gain territory.
"Why that was the right strategy to do is because it's the likes of Hansen who was securing the balls back, and other teammates, so [it's] pretty pleasing."
Outside the star performer, there were multiple positives for Farrell.
Another player was outstanding on his return to the number 10 position, the set piece and throw-in operated effectively and different teammate did not appear uncomfortable in his debut appearance in the front row.
But perhaps most satisfying for Farrell was Ireland bookending the game with two impressive spells.
Hansen's first couple of tries came in the first 11 minutes while additional teammates scored in the closing stages after the opposition had scored, ensuring the Irish side concluded on a high.
"I thought we really performed freely and attacked the match straight from the word go," said Farrell.
"The way we managed numerous elements during the game, especially them coming back just before half-time and regathering ourselves and producing a performance like we achieved in the later stages, I believed as far as territory and being familiar with most of our game in that second half was truly pleasing."
The might of South Africa are awaiting for Ireland, in what might be considered as an informal decider to the previous season's tied two-Test series on rival soil.
Farrell's side will need to reach another level to defeat the consecutive world champions, but the recent victory of the Australian team was a significant advancement in the right direction after an disappointing beginning to their fall schedule.
