After their previous disappointing showing against Japan, the head coach told his Irish squad to improve their game.
The team responded right away.
Ireland had struggled in the final stages against New Zealand and taken considerable time to find their rhythm versus Japan.
However, facing Australia, they began powerfully, with Mack Hansen shining most prominently during a comprehensive triumph that marked the team's best performance this year.
In his debut international start at the number 15 position, Hansen registered a hat-trick, contested excellently for aerial challenges and performed exceptionally against the country of his birth.
"You know, I've experienced a fairly challenging run with fitness issues really," the athlete commented.
"I missed being in this team, I understand there's considerable talk about me not exactly being raised here and I wasn't raised here, but I adore this team and this feels like family.
"Any time I get to play for the national team it's a privilege, if you fail to deliver a good showing you may not receive that privilege again.
"My whole approach this period was to take the field and do what I could do."
Coach stated: 'Excellent athletes require no excuses'
Following 28 appearances on the wing, Hansen was entrusted the full-back position for the initial time with multiple teammates injured.
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 squad.
After returned recently, he suffered a lower body injury that ruled him out for previous fixtures.
The coach had suggested that Hansen was particularly determined and these turned out to be not empty words as the former club player gave his manager a positive team headache for future matches.
"Well my first reaction were, 'You need to play excellently in those different coloured boots!'," commented the coach, referring to the player's decision to wear mismatched boots.
"In fact I thought that was appropriate but apparently Hansen just did that himself anyway. So he's drawn notice to himself before he's even started.
"I said to him before the match, 'Good players require no justifications, they can get on with it and just play naturally, you can get the man of the match if you choose,' and he responded, 'Yeah, I agree.'
"So he's that type of player, he prepares thoroughly, he's got a excellent approach to get across his preparation and so that's why he fitted straight back in and he was capable to be himself due to that."
The player's efforts also received praise from the opposing manager, who remarked he was the "exceptional Australian performer" on the evening.
"In my view he was super, his experience was evident to the fore," commented the former international manager.
"Unfortunately, Mack was likely the standout opposition performer on the field. He's got a excellent ability and he's such a good contender."
When asked about what makes Hansen a good fit at full-back, Farrell added: "Showing up in the center of the field is a trait that he does from the flank regardless, but I suppose he's better in position for that more often.
"His high ball play was brilliant, don't you think? I believed we persisted of doing the correct thing and that was putting the ball again on them to secure field position.
"The reason that was the correct strategy to do is because it's the likes of Mackie who was securing the balls back, and other teammates, so [it's] quite satisfying."
Beyond the star performer, there were numerous positives for the coach.
Another player was excellent on his comeback to the number 10 position, the scrum and throw-in functioned smoothly and another player did not appear uncomfortable in his first start in the front row.
But perhaps more pleasing for the manager was the team framing the game with two strong periods.
Hansen's first couple of tries occurred in the first 11 minutes while additional players registered in the closing exchanges after the other team had scored, ensuring the Irish team concluded on a positive note.
"In my opinion we really performed freely and approached the game right from the beginning," stated the coach.
"How we handled various aspects throughout the match, especially the opposition coming back just before the break and reorganizing ourselves and producing a display like we did in the second half, I believed as far as territory and being across the majority of our game in that second half was really satisfying."
The strength of South Africa are awaiting for Ireland, in what might be viewed as an unofficial decider to the previous season's tied multiple match contest on rival soil.
The coach's side will require to reach another level to beat the consecutive title holders, but the recent defeat of the Wallabies was a significant step in the correct path after an uninspiring beginning to their fall campaign.